Check in the atmophere editor. make sure that the part. Auto decay sunlight color is off. Or on the sky tab there is another spot that can give you a weird pull the color toward pink then the fog tab is one more place that could be giving you that problem set thos to 0. Finally the last tab. Effects. Check the all other light spot and the sun spot. It probibly coming from color shift. Turn that off. The other place it could be coming from is lens flare. Turn all that off too. It's easy to find just look around and turn off everything that looks pink or red. It's bleeding in from the default settings and the amount of lights you got happeneng there.