I use this mod with Terralith that add custom leaves color, somo of them are orange and they appear as they should in summer and spring, however in winter and fall they appear purple

It looks epic, imo. Keep it

happens to me on 1.18.2 as well

Heyy. As of version 2.0 all colormaps have been remade. Also I'm currently working on custom compatibility packs for biome mods so that shouldn't be an issues anymore. Here's the compatibility pack for Terralith: https://github.com/lucaargolo/fabric-seasons-terralith-compat