Yep, I made an arctic biome too, but I didn’t released it cause it was already an official biome, it would be rude to get something from radiant and claiming as my own, even though I made a lot of changes. (It had a lot of water like the archipelago, with taller mountains and icebergs.)
@Vargbane, this biome will be excellent for another mod, the bastioneers mod, a race using stone as main resource.
[Mod] (A20) The Bastioneers! More Dangerous (and Mod-Friendly) Than Ever! Help me test for A20! from @Wharp (Please, if you have time, update your mod too? 
)
Anyway, you mentioned that it will be green fields, so I’m confused. You could not change the color?