I use environment maps 99% of the time in Rhino. It would be really nice to see them more prevalent in MoI. If it were me, I would have the color picker be an environment map picker instead, but I completely understand the video card memory concerns. A 512x512x24 map is what, 6mb uncompressed? Not sure how small that would be as a dxtc texture or whatever direct3d uses these days. It just seems like an easy/straightforward way to optionally utilize more of the video card for (what I humbly assume to be) the majority of people using modern hardware.

In any case, it seems like you're generating one global environment map via your light definitions. Would it be possible to load this precalculated map from disk, so that we could simply replace it with our own until you have time to flesh out the style system and UI a bit more?