Background of Files panel

So a trivial thing to some I suppose - but the App Theme Choices in the newer versions of DW do not allow for white backgrounds for the various panels. Specifically, a white background for the Files Panel. I hate the light gray and would like very much to make it white. I have tried the main.less code with no success. My guess is it is much deeper - or not avaialbe at all. Hoping some hero can direct me to where I can fix this. It's odd to me that adobe would provide 4 choices of gray - and eliminate white altoghether.

thank you...