There's really no specific mod that deals with it, but there is a mod that can do what you are asking for. It is a customizable enb mod (graphics mod) with a little trainer like hud. It will have a whole bunch of editing in the game with options like ambient occlusions or artificial lighting(day and night, etc side along with evening, dusk, etc.) The mod will allow you to change lighting brightness, day saturation, etc. I tried this mod, and fiddled around with it. If you get a good set of numbers, then it will change the range of the colors for police cars. I know what you're talking about it. Trying the mod, it changed the range of the police colors or how for it refracts off objects. What I used : 45.000 75.000 75.000 etc. Yeah, you are probably confused. Trust me, when you use the mod, you'll figure it out to your desired choice. mod : http://www.youtube.com/watch?v=Ihn8W2mnfvo Or check out the enb website. Hope this helps out your request. :)