I couldn't find an updated colormap template for 1.20+, so I took a few hours out of my day and made one myself :)

This image can be used to change the color of the grass/leaves in Minecraft by saving it in: assets/minecraft/textures/colormap/[​grass/foliage].png

EDIT: I forgot to label it, but Old Growth Spruce Taiga and regular Taiga biomes use the same position on the image!!