I tried a white VC once, even with a nice coat of high temp clear. It eventually started turning kinda yellow from the heat and oil.
And I don't think it would be neccessary to have a white VC to point out leaks. It's kinda obvious if it's leaking from the VC no matter the color.
Speaking of white....here's a cool trick. To find leaks easily, pressure wash the engine as clean as possible. Then coat the suspected areas with Rightguard underarm deodorant spray. It puts a white chalky layer on that instantly turns brown when oil touches it.
Wiz