There's an ongoing discussion about the color intensity in USC on Steam Greenlight. For those who dislike the current visual world, I've made some quick adjustments to the engine to present a few choices with less intense colors and lighting.
If you're interested in this topic in any way, please let us know your opinion! Join the discussion at the Colors in USC board, or write to firstname.lastname@example.org. But first, look at the image below and select a preferred version--or any inbetween!
Also note that beside these options, it's also possible to reduce/remove only some colors which the community finds annoying. Nothing is carved into stone yet!
It's also important to know that base (ambient) light levels should be increased when using less lightning to counter Defense Value increase out of darkness and maintain difficulty. (Although super-hard missions were always intended to be super-dark--and there's a classy flare pistol! :D)