Issue Description: Custom biomes with custom foliage colors fail to show foliage colors properly on dynmap.

• Dynmap Version: Dynmap-3.1-beta4-spigot

• Server Version: Paper-244 (1.16.3)

• Pastebin of Configuration.txt: https://pastebin.com/d2xqxNJg

• Server Host (if applicable): Self hosted Ubuntu instance.

• Other Relevant Data/Screenshots:
  
  
  

• Steps to Replicate: Install Wild Worlds onto a singleplayer world and transfer onto a paper server then fullrender the world.

[x] I have looked at all other issues and this is not a duplicate
[x] I have been able to replicate this

Duplicate of #3438

Linking that one rather than this one due to activity

Same problem for me, Im on Paper latest version and dynmap doesn't render custom grass and leaves color in my world generation datapack.