how to use self defined colors in add_raster

[kongdd]

import leafmap
import leafmap.colormaps as cm

from matplotlib.colors import ListedColormap


cols = cm.get_palette('OrRd_r')
cmap = ListedColormap(cols)

m = leafmap.Map(center=(30.46001618003947, 114.61223316513498), zoom=11)

f_urban = "./Wuhan_Urban_GAIA_120D/urban_perc_2018.tif"

# cols = cm.palettes.OrRd_r.default
# cols

m.add_raster(f_urban, cmap=cmap, vmin=0, vmax=1, layer_name='perc_urban')
m

File [c:\ProgramData\Miniconda3\envs\geo\Lib\site-packages\leafmap\leafmap.py:1881](file:///C:/ProgramData/Miniconda3/envs/geo/Lib/site-packages/leafmap/leafmap.py:1881), in Map.add_raster(self, source, band, palette, vmin, vmax, nodata, attribution, layer_name, zoom_to_layer, **kwargs)
   1848 def add_raster(
   1849     self,
   1850     source,
   (...)
   1859     **kwargs,
   1860 ):
   1861     """Add a local raster dataset to the map.
   1862         If you are using this function in JupyterHub on a remote server (e.g., Binder, Microsoft Planetary Computer) and
   1863         if the raster does not render properly, try installing jupyter-server-proxy using `pip install jupyter-server-proxy`,
...
---> 68     raise ValueError(
     69         f"Please use a valid matplotlib colormap name or palettable palette name. Invalid: {name}"
     70     )

ValueError: Please use a valid matplotlib colormap name or palettable palette name. Invalid: <matplotlib.colors.ListedColormap object at 0x0000029663722B10>
Output is truncated. View as a [scrollable element](command:cellOutput.enableScrolling?62ab63ec-e0e1-4ca8-929a-01aa6c0b7147) or open in a [text editor](command:workbench.action.openLargeOutput?62ab63ec-e0e1-4ca8-929a-01aa6c0b7147). Adjust cell output [settings](command:workbench.action.openSettings?%5B%22%40tag%3AnotebookOutputLayout%22%5D)...

[giswqs]

The cmap parameter accepts a matplotlib colormap0 string or a list of hex color codes.

m.add_raster(dem, cmap='OrRd_r', layer_name="DEM")
m.add_raster(dem, cmap=['#ff0000', '#ffff00', '#0000ff'], layer_name="DEM2")

[kongdd]

It seems that get_palette returned colors missed a # in the head.

cols = cm.get_palette('OrRd_r')
m.add_raster(dem, cmap=cols, layer_name="DEM2") # failed

cols = cm.get_palette('OrRd')
cols = ['#' + c for c in cols]
m.add_raster(dem, cmap=cols, layer_name="DEM2") # works

[giswqs]

Missging the "#"

cols = ["#" + col for col in cols]

[kongdd]

Got it. Thank u

[giswqs]

Right. Without the "#", it is treated as a color name, such as 'red', 'yellow', etc. Not as a hex color code.

[giswqs]

For example.

m.add_raster(dem, cmap=['red', 'green', 'blue'], layer_name="DEM")