Overcast texture color

Hi all:I noticed after installing REX for FS9 that the overcast cloud texture color had a bluish tint to it, not grey as what I was observing out my window. Installing Environment Indigo 1.5 Final rendered a grey overcast texture color. Just wondering what texture file(s) control the overcast color? I submitted this question on the REX forum but have not received an answer. Thought I'd post it here for in hopes that someone might know the answer.Thx