question

In the 21.2 Beta the color tab was added to the state chart template, allowing you to use palettes the same way as in other charts.

In 21.1 you can still make the chart use a custom palette by assigning it to the "palette" node in the charts variables in the tree. Insert the name of the chart and palette and run the following code in the script window.

string chartName = "<Name of the chart>";
string paletteName = "<Name of the palette>";

treenode chartPalette = Model.find("/Tools/Statistics/" + chartName + ">variables/palette");
treenode statePalette = Model.find("/Tools/ColorPalettes/" + paletteName);
chartPalette.value = statePalette;

This will take priority over the internal palette of the chart.

The custom palette should be formatted like in the picture; the order of the states does not matter, states that are missing from the palette will be filled in automatically the first time the chart is populated.

Note that the properties of the chart still shows the internal palette, but the colors used are the custom ones.

Addendum: I also tried overwriting the color values of the internal palette via code, but ran into issues with the alpha value staying at/resetting back to the default value. This can be circumvented by having the properties open when assigning the new colors and clicking on each color after running the code to properly update it. As this would still be a lot of work if you have a lot of charts the method above seems to be the easier one.