diff --git a/batch/colorschemes.php b/batch/colorschemes.php
new file mode 100644
index 0000000000..938296c85a
--- /dev/null
+++ b/batch/colorschemes.php
@@ -0,0 +1,163 @@
+<?php
+// colorschemes.php -- HotCRP script for analyzing color schemes
+// Copyright (c) 2006-2023 Eddie Kohler; see LICENSE.
+
+if (realpath($_SERVER["PHP_SELF"]) === __FILE__) {
+    require_once(dirname(__DIR__) . "/src/init.php");
+    exit(ColorSchemes_Batch::make_args($argv)->run());
+}
+
+class ColorSchemes_Batch {
+    /** @var array<string,array{0|1|2,int,?string}> */
+    public $schemes = [];
+    /** @var array<string,list<string>> */
+    public $colors = [];
+    /** @var ?list<string> */
+    public $gradient;
+    /** @var bool */
+    public $php = false;
+
+    function __construct($arg) {
+        if (isset($arg["gradient"])) {
+            $this->gradient = $arg["gradient"];
+        } else if (isset($arg["php"])) {
+            $this->php = true;
+        }
+        foreach (Discrete_ReviewField::$scheme_info as $name => $sch) {
+            $this->schemes[$name] = $sch;
+            if ($sch[0] !== 1) {
+                $this->colors[$name] = array_fill(0, $sch[1], null);
+            }
+        }
+        $this->colors["none"][0] = "222222";
+    }
+
+    /** @param string $s
+     * @return OklchColor */
+    function from_hashcolor($s) {
+        $p = strlen($s) === 7 ? 1 : 0;
+        return OklchColor::from_rgb(intval(substr($s, $p, 2), 16),
+                                    intval(substr($s, $p + 2, 2), 16),
+                                    intval(substr($s, $p + 4, 2), 16));
+    }
+
+    /** @return int */
+    function run_gradient() {
+        $mode = $this->gradient[3] ?? "shorter";
+        if (count($this->gradient) < 3
+            || count($this->gradient) > 4
+            || !ctype_digit($this->gradient[0])
+            || ($n = intval($this->gradient[0])) < 2
+            || !preg_match('/\A#?([0-9a-fA-F]{6})\z/', $this->gradient[1], $m1)
+            || !preg_match('/\A#?([0-9a-fA-F]{6})\z/', $this->gradient[2], $m2)
+            || !in_array($mode, ["shorter", "longer", "increasing", "decreasing"])) {
+            throw new CommandLineException("`--gradient` expects NSTOPS COLOR1 COLOR2 [longer]");
+        }
+        $c1 = self::from_hashcolor($m1[1]);
+        $c2 = self::from_hashcolor($m2[1]);
+        if (is_nan($c1->okh) && is_nan($c2->okh)) {
+            $c1->okh = $c2->okh = 0;
+        } else if (is_nan($c1->okh)) {
+            $c1->okh = $c2->okh;
+        } else if (is_nan($c2->okh)) {
+            $c2->okh = $c1->okh;
+        }
+        $hi = HclColor::hue_interpolate($c1->okh, $c2->okh, $mode);
+        for ($i = 0; $i < $n; ++$i) {
+            if ($i === 0) {
+                $c = $c1;
+            } else if ($i === $n - 1) {
+                $c = $c2;
+            } else {
+                $c = $c1->interpolate($i / ($n - 1), $c2, $hi);
+            }
+            fwrite(STDOUT, strtolower($c->hashcolor()) . "\n");
+        }
+        return 0;
+    }
+
+    private function write_php($j) {
+        $col = [];
+        $cat = [];
+        $rev = [];
+        foreach ($this->schemes as $name => $sch) {
+            if ($sch[0] === 2) {
+                $cat[] = "\"{$name}\" => true";
+            }
+            if ($sch[0] !== 1) {
+                $col[] = "\"{$name}\" => \"{$j[$name]->colors}\"";
+            }
+            if ($sch[2]) {
+                $rev[] = "\"{$name}\" => \"{$sch[2]}\"";
+            }
+        }
+        fwrite(STDOUT, "    public static \$scheme_colors = [" . join(", ", $col) . "];\n"
+            . "    public static \$scheme_categorical = [" . join(", ", $cat) . "];\n"
+            . "    public static \$scheme_reverse = [" . join(", ", $rev) . "];\n");
+    }
+
+    /** @return int */
+    function run() {
+        if (isset($this->gradient)) {
+            return $this->run_gradient();
+        }
+        $css = file_get_contents(SiteLoader::$root . "/stylesheets/style.css");
+        preg_match_all('/^\.sv-?([a-z]*)(\d+)\s*\{\s*color\s*:\s*#([0-9a-fA-F]{6})\s*;(?:\s|\/\*.*?\*\/)*\}/m', $css, $ms, PREG_SET_ORDER);
+        foreach ($ms as $mx) {
+            $name = $mx[1] === "" ? "sv" : $mx[1];
+            $idx = intval($mx[2]);
+            $color = strtolower($mx[3]);
+            if (!isset($this->schemes[$name])
+                || $this->schemes[$name][0] === 1
+                || $idx <= 0
+                || $idx > $this->schemes[$name][1]
+                || isset($this->colors[$name][$idx - 1])) {
+                fwrite(STDERR, "Unexpected color {$mx[0]}\n");
+            } else {
+                $this->colors[$name][$idx - 1] = $color;
+            }
+        }
+        $j = [];
+        foreach ($this->schemes as $name => $sch) {
+            if ($sch[0] === 1) {
+                continue;
+            }
+            if (!isset($this->colors[$name])
+                || count(array_filter($this->colors[$name])) !== $sch[1]) {
+                fwrite(STDERR, "Some colors not set for scheme {$name}\n");
+            } else {
+                $j[$name] = $jx = (object) [];
+                if ($sch[0] === 2) {
+                    $jx->categorical = true;
+                }
+                $jx->colors = join("", $this->colors[$name]);
+            }
+        }
+        if ($this->php) {
+            $this->write_php($j);
+        } else {
+            foreach ($this->schemes as $name => $sch) {
+                if ($sch[0] === 1 && isset($j[$sch[2]])) {
+                    $j[$sch[2]]->reverse = $name;
+                }
+            }
+            fwrite(STDOUT, json_encode($j, JSON_PRETTY_PRINT) . "\n");
+        }
+        return 0;
+    }
+
+    /** @return ColorSchemes_Batch */
+    static function make_args($argv) {
+        $arg = (new Getopt)->long(
+            "help,h !",
+            "php",
+            "gradient[]+,g[]+ Compute gradient"
+        )->description("Analyze HotCRP CSS color schemes.
+Usage: php batch/colorschemes.php")
+         ->helpopt("help")
+         ->maxarg(0)
+         ->parse($argv);
+
+        return new ColorSchemes_Batch($arg);
+    }
+}
diff --git a/scripts/graph.js b/scripts/graph.js
index 0994d2b787..b26de212f5 100644
--- a/scripts/graph.js
+++ b/scripts/graph.js
@@ -1481,7 +1481,7 @@ function score_ticks(rf) {
         rewrite: function () {
             this.selectAll("g.tick text").each(function () {
                 var d = d3.select(this), value = +d.text();
-                d.attr("fill", rf.rgb(value));
+                d.attr("fill", rf.color(value));
                 if (!rf.default_numeric && value)
                     d.text(rf.unparse_symbol(value, split));
             });
diff --git a/scripts/script.js b/scripts/script.js
index b3e799a3bb..32541a4bff 100644
--- a/scripts/script.js
+++ b/scripts/script.js
@@ -6010,8 +6010,8 @@ DiscreteValues_ReviewField.prototype.parse_value = function (txt) {
     return si >= 0 ? this.value_info(si + 1) : null;
 };
 
-DiscreteValues_ReviewField.prototype.rgb = function (val) {
-    return this.scheme_info.rgb(val);
+DiscreteValues_ReviewField.prototype.color = function (val) {
+    return this.scheme_info.color(val);
 };
 
 DiscreteValues_ReviewField.prototype.className = function (val) {
@@ -6100,8 +6100,8 @@ Checkbox_ReviewField.prototype.parse_value = function (txt) {
     return null;
 };
 
-Checkbox_ReviewField.prototype.rgb = function (val) {
-    return this.scheme_info.rgb(val ? 2 : 1);
+Checkbox_ReviewField.prototype.color = function (val) {
+    return this.scheme_info.color(val ? 2 : 1);
 };
 
 Checkbox_ReviewField.prototype.className = function (val) {
@@ -12720,7 +12720,7 @@ return function (n, scheme, flip) {
         categorical: (sci[0] & 2) !== 0,
         max: sci[1],
         rgb_array: rgb_array,
-        rgb: function (val) {
+        color: function (val) {
             var x = rgb_array(val);
             return sprintf("#%02x%02x%02x", x[0], x[1], x[2]);
         },
diff --git a/scripts/settings.js b/scripts/settings.js
index fca77cbeac..34fb62db07 100644
--- a/scripts/settings.js
+++ b/scripts/settings.js
@@ -723,12 +723,16 @@ function rf_color() {
     }
     for (i = 1; i <= scheme.max && c; ++i) {
         if (c.children.length < i)
-            $(c).append('<svg width="0.5em" height="0.75em" viewBox="0 0 1 1"><path d="M0 0h1v1h-1z" fill="currentColor" /></svg>');
+            $(c).append('<svg width="0.75em" height="0.75em" viewBox="0 0 1 1"><path d="M0 0h1v1h-1z" fill="currentColor" /></svg>');
         c.children[i - 1].setAttribute("class", scheme.className(i));
     }
     while (c && i <= c.children.length) {
         c.removeChild(c.lastChild);
     }
+    /*c.append($e("br"), $e("span", {
+        "class": "d-inline-block",
+        "style": "width:" + (0.75 * scheme.max) + "em;height:1em;background:linear-gradient(in oklch to right, " + scheme.color(1) + " 0% " + (50 / scheme.max) + "%, " + scheme.color(scheme.max) + " " + (100 - 50 / scheme.max) + "% 100%)"
+    }));*/
 }
 
 handle_ui.on("change.rf-scheme", rf_color);
diff --git a/src/pages/p_scorechart.php b/src/pages/p_scorechart.php
index 876d7b6352..e13b558a88 100644
--- a/src/pages/p_scorechart.php
+++ b/src/pages/p_scorechart.php
@@ -24,6 +24,20 @@ class Scorechart_Page {
     private $hiLabel;
     /** @var bool */
     private $flip;
+    /** @var string */
+    private $scheme;
+    /** @var int */
+    private $scheme_max;
+    /** @var bool */
+    private $categorical;
+    /** @var bool */
+    private $svflip;
+    /** @var int */
+    private $scale;
+
+    public static $scheme_colors = ["sv" => "9c3131a04b00a26300a179009d8f00929e007fad005fbd0000cc00", "bupu" => "4b8bc14181be3b76bb396bb73b5fb24053ab4646a34d389a54278f", "pkrd" => "e14da0d7448bcc3b76c13363b52b50a9243e9c1e2c8f1819821201", "viridis" => "440154472c7a3b518b2c718e21908d27ad815cc863aadc32dbcb39", "orbu" => "fca636f68443e86659d14d6fb23a818e2c8f6721963e15940d0887", "turbo" => "23171b4569ee26bce13ff3936be619ecd12eff821dcb2f0d900c00", "catx" => "1f77b4ff7f0e2ca02cd627289467bd8c564be377c27f7f7fbcbd2217becf", "none" => "222222"];
+    public static $scheme_categorical = ["catx" => true, "none" => true];
+    public static $scheme_reverse = ["sv" => "svr", "svr" => "sv", "bupu" => "pubu", "pubu" => "bupu", "rdpk" => "pkrd", "pkrd" => "rdpk", "viridisr" => "viridis", "viridis" => "viridisr", "orbu" => "buor", "buor" => "orbu", "turbo" => "turbor", "turbor" => "turbo"];
 
     /** @param array{int,int,int} $c1
      * @param array{int,int,int} $c2
@@ -35,7 +49,7 @@ static function quality_color($c1, $c2, $f) {
                 (int) ($c2[2] * $f + $c1[2] * (1 - $f) + 0.5)];
     }
 
-    function __construct($v, $h, $lo, $hi, $flip) {
+    function __construct($v, $h, $lo, $hi, $flip, $sv, $scale) {
         foreach (explode(",", $v) as $value) {
             if ($value !== "") {
                 $value = intval($value);
@@ -49,8 +63,18 @@ function __construct($v, $h, $lo, $hi, $flip) {
             $this->valLight = $h;
         }
         $this->loLabel = $lo ?? "1";
-        $this->hiLabel = $hi ?? (string) $this->valMax;
-        $this->flip = $flip;
+        $this->hiLabel = $hi ?? (string) ($this->valMax - 1);
+        $this->flip = $this->svflip = $flip;
+        if (!isset(self::$scheme_colors[$sv]) && isset(self::$scheme_reverse[$sv])) {
+            $this->svflip = !$this->svflip;
+            $sv = self::$scheme_reverse[$sv];
+        } else if (!isset(self::$scheme_colors[$sv])) {
+            $sv = "sv";
+        }
+        $this->scheme = $sv;
+        $this->scheme_max = strlen(self::$scheme_colors[$sv]) / 6;
+        $this->categorical = self::$scheme_categorical[$sv] ?? false;
+        $this->scale = intval($scale);
     }
 
     static function cacheable_headers() {
@@ -70,26 +94,49 @@ static function fail($status, $text, $cacheable) {
         echo $text, "\r\n";
     }
 
+    /** @return array{int,int,int} */
+    private function rgb_array($i) {
+        $n = $this->valMax - 1;
+        if ($n <= 1 || $this->scheme_max <= 1) {
+            $f9 = $this->svflip ? 1 : $this->scheme_max;
+        } else if ($this->categorical && $this->svflip) {
+            $f9 = ($n - $i) % $this->scheme_max + 1;
+        } else if ($this->categorical) {
+            $f9 = ($i - 1) % $this->scheme_max + 1;
+        } else {
+            $f = ($this->scheme_max - 1) / ($n - 1);
+            if ($this->svflip) {
+                $f9 = max(min(round(($n - $i) * $f) + 1, $this->scheme_max), 1);
+            } else {
+                $f9 = max(min(round(($i - 1) * $f) + 1, $this->scheme_max), 1);
+            }
+        }
+        $k = intval(substr(self::$scheme_colors[$this->scheme], ($f9 - 1) * 6, 6), 16);
+        return [$k >> 16, ($k >> 8) & 255, $k & 255];
+    }
+
     private function make_s1() {
+        $scale = $this->scale;
+
         // set shape constants
-        $blockHeight = $blockWidth = 3;
-        $blockSkip = 2;
-        $blockPad = 2;
+        $blockHeight = $blockWidth = 3 * $scale;
+        $blockSkip = 2 * $scale;
+        $blockPad = 2 * $scale;
 
         $maxY = max($this->maxY, 3);
         $picWidth = ($blockWidth + $blockPad) * ($this->valMax - 1)
             + $blockPad;
         $picHeight = $blockHeight * $maxY + $blockSkip * ($maxY + 1);
-        $pic = @imagecreate($picWidth + 1, $picHeight + 1);
+        $pic = @imagecreate($picWidth + 2 * $scale, $picHeight + $scale);
 
         $cWhite = imagecolorallocate($pic, 255, 255, 255);
         $cBlack = imagecolorallocate($pic, 0, 0, 0);
         $cgray = imagecolorallocate($pic, 190, 190, 255);
 
         imagecolortransparent($pic, $cWhite);
-        imagefilledrectangle($pic, 0, $picHeight, $picWidth + 1, $picHeight + 1, $cgray);
-        imagefilledrectangle($pic, 0, $picHeight - $blockHeight - $blockPad, 0, $picHeight + 1, $cgray);
-        imagefilledrectangle($pic, $picWidth, $picHeight - $blockHeight - $blockPad, $picWidth + 1, $picHeight + 1, $cgray);
+        imagefilledrectangle($pic, 0, $picHeight, $picWidth + 2 * $scale, $picHeight + $scale, $cgray);
+        imagefilledrectangle($pic, 0, $picHeight - $blockHeight - $blockPad, $scale - 1, $picHeight + $scale, $cgray);
+        imagefilledrectangle($pic, $picWidth + $scale, $picHeight - $blockHeight - $blockPad, $picWidth + 2 * $scale, $picHeight + $scale, $cgray);
 
         $cv_black = [0, 0, 0];
         $cv_bad = [200, 128, 128];
@@ -99,11 +146,10 @@ private function make_s1() {
         for ($value = 1; $value < $this->valMax; $value++) {
             $vpos = $this->flip ? $this->valMax - $value : $value;
             $height = $this->values[$vpos];
-            $frac = ($vpos - 1) / ($this->valMax - 1);
-            $cv_cur = self::quality_color($cv_bad, $cv_good, $frac);
+            $cv_cur = $this->rgb_array($vpos);
             $cFill = imagecolorallocate($pic, $cv_cur[0], $cv_cur[1], $cv_cur[2]);
 
-            $curX = $blockWidth * ($value - 1) + $blockPad * $value;
+            $curX = $blockWidth * ($value - 1) + $blockPad * $value + $scale - 1;
             $curY = $picHeight - ($blockHeight + $blockSkip) * $height + $blockHeight;
 
             for ($h = 1; $h <= $height; $h++) {
@@ -117,22 +163,23 @@ private function make_s1() {
             }
         }
 
-        $lx = $blockPad;
-        $rx = $picWidth - $blockWidth - $blockPad;
-        $y = $picHeight - $blockHeight - $blockSkip - 3;
+        $font = $scale > 2 ? 5 : 1;
+        $lx = $blockPad + $scale - 1;
+        $rx = $picWidth - $blockWidth - $blockPad + $scale - 1;
+        $y = $picHeight - $blockSkip + 2 - imagefontheight($font);
         if ($this->values[$this->flip ? $this->valMax - 1 : 1] === 0) {
-            imagestring($pic, 1, $lx, $y, $this->loLabel, $cgray);
+            imagestring($pic, $font, $lx, $y, $this->loLabel, $cgray);
         }
         if ($this->values[$this->flip ? 1 : $this->valMax - 1] === 0) {
-            imagestring($pic, 1, $rx, $y, $this->hiLabel, $cgray);
+            imagestring($pic, $font, $rx, $y, $this->hiLabel, $cgray);
         }
 
         return $pic;
     }
 
     private function make_s2() {
-        $picWidth = 64;
-        $picHeight = 8;
+        $picWidth = 64 * $this->scale;
+        $picHeight = 8 * $this->scale;
         $pic = @imagecreate($picWidth, $picHeight);
 
         $bg = imagecolorallocate($pic, 255, 255, 255);
@@ -146,11 +193,10 @@ private function make_s2() {
             $vpos = $this->flip ? $this->valMax - $value : $value;
             $height = $this->values[$vpos];
             if ($height > 0) {
-                $frac = ($vpos - 1) / ($this->valMax - 1);
-                $cv_cur = self::quality_color($cv_bad, $cv_good, $frac);
+                $cv_cur = $this->rgb_array($vpos);
                 $cFill = imagecolorallocate($pic, $cv_cur[0], $cv_cur[1], $cv_cur[2]);
-                imagefilledrectangle($pic, ($picWidth + 1) * $pos / $this->sum, 0,
-                                     ($picWidth + 1) * ($pos + $height) / $this->sum - 2, $picHeight,
+                imagefilledrectangle($pic, ($picWidth + $this->scale) * $pos / $this->sum, 0,
+                                     ($picWidth + $this->scale) * ($pos + $height) / $this->sum - 2 * $this->scale, $picHeight,
                                      $cFill);
                 $pos += $height;
             }
@@ -166,6 +212,8 @@ static function go_param($params) {
         $lo = $params["lo"] ?? null;
         $hi = $params["hi"] ?? null;
         $flip = !!($params["flip"] ?? null);
+        $sv = $params["sv"] ?? "sv";
+        $scale = $params["scale"] ?? "1";
 
         if ($v === null
             || ($v !== "" && !preg_match('/\A\d+(,\d+)*\z/', $v))
@@ -173,7 +221,8 @@ static function go_param($params) {
             || !ctype_digit($s)
             || ($sn = intval($s)) < 1
             || $sn > 2
-            || ($h !== null && !ctype_digit($h))) {
+            || ($h !== null && !ctype_digit($h))
+            || !ctype_digit($scale)) {
             self::fail("400 Bad Request", "Invalid parameters", true);
             return;
         }
@@ -193,7 +242,7 @@ static function go_param($params) {
         self::cacheable_headers();
         header("Content-Type: image/png");
 
-        $sc = new Scorechart_Page($v, $h !== null ? intval($h) : null, $lo, $hi, $flip);
+        $sc = new Scorechart_Page($v, $h !== null ? intval($h) : null, $lo, $hi, $flip, $sv, $scale);
         if ($sn !== 2) {
             imagepng($sc->make_s1());
         } else {
diff --git a/stylesheets/style.css b/stylesheets/style.css
index 2003efa1fe..4439acddec 100644
--- a/stylesheets/style.css
+++ b/stylesheets/style.css
@@ -5128,36 +5128,36 @@ div.sc {
 .sv-catx9 { color: #bcbd22; }
 .sv-catx10 { color: #17becf; }
 .sv-orbu1 { color: #fca636; }
-.sv-orbu2 { color: #f2844b; }
-.sv-orbu3 { color: #e16462; }
-.sv-orbu4 { color: #cc4778; }
-.sv-orbu5 { color: #b12a90; }
-.sv-orbu6 { color: #8f0da4; }
-.sv-orbu7 { color: #6a00a8; }
-.sv-orbu8 { color: #41049d; }
+.sv-orbu2 { color: #f68443; }
+.sv-orbu3 { color: #e86659; }
+.sv-orbu4 { color: #d14d6f; }
+.sv-orbu5 { color: #b23a81; }
+.sv-orbu6 { color: #8e2c8f; }
+.sv-orbu7 { color: #672196; }
+.sv-orbu8 { color: #3e1594; }
 .sv-orbu9 { color: #0d0887; }
 .dark .sv-orbu6 { color: #a719bd; }
 .dark .sv-orbu7 { color: #8c34bf; }
 .dark .sv-orbu8 { color: #6e37bf; }
 .dark .sv-orbu9 { color: #5350b5; }
 .sv-pkrd1 { color: #e14da0; }
-.sv-pkrd2 { color: #e2368e; }
-.sv-pkrd3 { color: #dd247a; }
-.sv-pkrd4 { color: #d21865; }
-.sv-pkrd5 { color: #c10f55; }
-.sv-pkrd6 { color: #ab0749; }
-.sv-pkrd7 { color: #94023d; }
-.sv-pkrd8 { color: #7d002f; }
-.sv-pkrd9 { color: #67001f; }
-.sv-pkrd1 { color: #e14da0; }
-.sv-pkrd2 { color: #da498e; }
-.sv-pkrd3 { color: #d4457c; }
-.sv-pkrd4 { color: #cd416a; }
-.sv-pkrd5 { color: #c73d59; }
-.sv-pkrd6 { color: #c03847; }
-.sv-pkrd7 { color: #b93435; }
-.sv-pkrd8 { color: #b33023; }
-.sv-pkrd9 { color: #ac2c11; }
+.sv-pkrd2 { color: #d7448b; }
+.sv-pkrd3 { color: #cc3b76; }
+.sv-pkrd4 { color: #c13363; }
+.sv-pkrd5 { color: #b52b50; }
+.sv-pkrd6 { color: #a9243e; }
+.sv-pkrd7 { color: #9c1e2c; }
+.sv-pkrd8 { color: #8f1819; }
+.sv-pkrd9 { color: #821201; }
+.dark .sv-pkrd1 { color: #e14da0; }
+.dark .sv-pkrd2 { color: #dd478e; }
+.dark .sv-pkrd3 { color: #d8417d; }
+.dark .sv-pkrd4 { color: #d23c6c; }
+.dark .sv-pkrd5 { color: #cb375b; }
+.dark .sv-pkrd6 { color: #c4344b; }
+.dark .sv-pkrd7 { color: #bd303a; }
+.dark .sv-pkrd8 { color: #b52e28; }
+.dark .sv-pkrd9 { color: #ac2c11; }
 .sv-turbo1 { color: #23171b; }
 .sv-turbo2 { color: #4569ee; }
 .sv-turbo3 { color: #26bce1; }