Very often, lower level resolutions cannot manage color gradations as well as higher resolutions. Not enough pixels on screen for the software to do its rendering efficiently. Levels of gradation my be lost, and the image will be higher in overall gamma and may appear washed out.
As for the hair changing colors...yee...
... That's not the first time I've seen that, but I don't remember anyone talking about yellow or purple before. That's...interesting. Here's my guess: reflected light. The hair is orange in the pics because it's picking up warm light from a source somewhere nearby. Torch or candle or something. Maybe sunset light through a window / hole? Same with the caves, it seems to be reflecting the
lack of light, if that makes sense: rather than not being lit...it's
reflecting the surrounding darkness. So it seems like it might be an issue with the shaders of the hair textures.
Your game does seem a bit washed-out. That's mostly a matter of the color settings on your TV or monitor. The gamma is pretty high, from what I can see.
