I think that I might have an idea as to where the problem lies: My shaders take their colour from the given vertices. However, the environment--being a quick test-room--has no vertex-colours, nor a material to specify that they should be used. It may be that some cards--my own presumably included--deal with this by providing the colour white, while other cards--yours included, I imagine--do... well, something else. This seems to be borne out by the fact that the player's arms and the enemies--which should have vertex-colours--appear to be correctly rendered.
If so, then the problem should disappear when I create some proper environments.
(Having seen it in the video that you posted, I am now somewhat tempted to go with a blue colour-scheme for the environments, rather than the white that I previously had in mind...)
I think that sounds very much like the root cause, particularly since everything else seemed to render perfectly fine. Toss me another build when you get the environment properly colored and i'll let you know if their's still issues. I'll hold off booting up my other machine to run another test for now.