Too much light on grass

Hi! I am making a fps game, and i put some police vehicles in the scene. Unfortunelly, they had no flash\siren so i made 3 lights for each vehicle. The lights are blue,red,and white. But i have a problem! The grass near the vehicles are TOO BRIGHT! It's making it "unconfortable to see". How can i stop the lights from brightening the grass whitout changing it's appearence (the lights appearence) ? I need the lights to be seen, but i also need the shadows on the grass and they are SO BRIGHT =C ![alt text][1] [1]: /storage/temp/76932-brightgrassproblem.png