@zukow I with the help of one of the authors of some DOSBox fork start to dealing with that "bad colors" in HUGI and other games that use 65k colors. It's all about DOSBox in the end, not supporting properly bgra and stuff. Even taking a screenshot via "ctrl+f5" is broken. Once we will deal with, I of course will share necessary changes.
Btw, is OpenGL mode slower, faster or the same for you? For example in quake1. Or there is some other good benchmark "PCNBench". Because OpenGL there just as blitter, which mean every frame take time => can be slower. Only bonus there to have scaling for free via it.