I've been blighted by those pesky Fallout NV gremlins, and they just wont rest! First, after 4 hours of gameplay, the rainbows started appearing(the skybox was broken, apparently) so i changed the video settings to a little higher, and discovered, that it was the cure... a temporary one... so after an another fierce half hour of wasteland wandering and mis-adventuring, the rainbows popped up again... so, this was the limit of my crappy laptop, and I couldn't push the settings any higher, or the game would be unplayable... Leave yer smart arse responses on the current situation, might have a laugh in the end