The Pig Iron Productions blog has a new post with a photo of the green for a new sprue of Kolony Ferals heads.
From their website:
We thought it was about time we did a workbench update. What we have here is a new sprue green for the Ferals with bladed weapons we are working on at the moment. These heads represent Ferals which have removed some or all of their protective wrappings and show how twisted they have become over the decades. Most heads feature some kind of crude cybernetic implants and twisted, mutated features which would also work well on our existing rebel figures.
They will be part of the next pack and also be released as separate sprues for conversion fans.