I wanted to make the snowy leaves from that better foliage mod but got told you can't, so I instead cheated using optifine to make a snowy version of the spruce leaves depending on which biome they're in!
I changed the spruce model to have cube_bottom_up as parent, and made 2 new texture for the bottom and top respectively.
This makes it so that the leaf doesn't follow the colormap given by the game, but seeing as spruce doesn't change colour ever, I just made the textures green in the png itself.
As for the snow, I made a ctm that would replace the spruce tiles with snowy ones depending on the biome. I have 3 .properties files:
Yeah but doesnt that make the entire leaf block white? And is there any way to get like a template of the biomes but in the grid format since i like the default colors or do i just have to do that myself? Im quite new to resource packs/optfine so im still learning.
You can create an overlay texture so the colormap only affects certain pixels. That's how grass blocks change colors in different biomes but the dirt remains the same. I posted a grid format for vanilla grass in the discussion format which is pretty close to the foliage colormap.