diff --git a/src/lib/components/colors/Header.svelte b/src/lib/components/colors/Header.svelte
index 11b96c5f..77d3c363 100644
--- a/src/lib/components/colors/Header.svelte
+++ b/src/lib/components/colors/Header.svelte
@@ -42,8 +42,17 @@
       try {
         newColor = to(value, targetSpace, { inGamut: true });
       } catch (error) {
-        hasError = true;
-        console.error(error);
+        try {
+          // If it's possibly hex without a hash, add a hash and try again.
+          if ([3, 4, 6, 8].includes(value.length)) {
+            newColor = to(`#${value}`, targetSpace, { inGamut: true });
+          }
+          // eslint-disable-next-line @typescript-eslint/no-unused-vars
+        } catch (errorWithHash) {
+          hasError = true;
+          // Log original error
+          console.error(error);
+        }
       }
       if (newColor) {
         $color = newColor;
diff --git a/test/lib/components/colors/Header.spec.ts b/test/lib/components/colors/Header.spec.ts
index 7849c24f..aed32aab 100644
--- a/test/lib/components/colors/Header.spec.ts
+++ b/test/lib/components/colors/Header.spec.ts
@@ -23,6 +23,40 @@ describe('Header', () => {
     expect(actual.coords).toEqual([0, 100, 50]);
   });
 
+  it('handles hex with a preceding hash', async () => {
+    const color = writable(HSL_WHITE);
+    const { getByLabelText } = render(Header, {
+      type: 'bg',
+      color,
+      format: 'hsl',
+    });
+    const input = getByLabelText('Background Color');
+    await fireEvent.focus(input);
+    await fireEvent.input(input, { target: { value: '#f00' } });
+    await fireEvent.blur(input);
+    const actual = get(color);
+
+    expect(actual.space).toEqual(HSL);
+    expect(actual.coords).toEqual([0, 100, 50]);
+  });
+
+  it('handles hex without a preceding hash', async () => {
+    const color = writable(HSL_WHITE);
+    const { getByLabelText } = render(Header, {
+      type: 'bg',
+      color,
+      format: 'hsl',
+    });
+    const input = getByLabelText('Background Color');
+    await fireEvent.focus(input);
+    await fireEvent.input(input, { target: { value: 'f00' } });
+    await fireEvent.blur(input);
+    const actual = get(color);
+
+    expect(actual.space).toEqual(HSL);
+    expect(actual.coords).toEqual([0, 100, 50]);
+  });
+
   it('shows error on invalid color', async () => {
     vi.spyOn(console, 'error').mockImplementation(() => {
       /* do nothing */