The line has to be drawn somewhere. People don't like playing against players that have an unfair advantage. How would you know if they have unfair textures so you can avoid playing against them? Being able to see players better gives you an advantage, just like wallhacks or aimbots. How much of an advantage is debatable, but it is there, and it upsets some people.
I understand your point of view Jit, but i think right now you are going way "ban everything that isn't official". I agree light-color barrels made big change, but i don't think it's case with grass that's a little lighter than original.
I think that textures that have color quite close to player textures of certain teams should be controlled a bit, but we don't have team green...
Anyway another issue is that players have brightness set up very high, and for example: i cannot complete towerjump because it's simply too dark for me, and most players do it, because their brightness is set very high, even author was not aware that it is simply too dark under normal brightness settings... I think that this should be next issue to resolve...
