I'm making a resource pack & using OptiFine's colour map features, but I've run into an issue where my grass colour map is overwriting the colour map for the swamp grass. If anyone knows how to fix this problem I'd be grateful.
Yeah but it's being overwritten by my colourmap for other grass
OK, now I'm just confused. Your response to Katja indicated to me that changing your regular colormap didn't affect the swamp. I might have misunderstood that part. Sorry.
Regardless, if your regular colormap is affecting the swamp then just change the regular colormap to be how you want it. You really don't need a dedicated swamp color map since it's just one biome. The swamp is just one tiny little dot on the vanilla-style map, and the same type of bar as everything else on Optifine's version.
If you're using the vanilla method, here's a map of them:
I'm not sure what to suggest beyond that. I suppose submitting a ticket to Optifine's bug tracker stating that the swampgrass.png file isn't working as expected and giving as much information as possible about what you've done in hopes that it'll get fixed.
The main thing was in vanilla the swamp has 2 different colours that it mixes between & I can't get that effect with the standard colour map. Not a big deal just something small & nitpicky. Thanks for trying to help out.