Label Group Color Schemes

Does anyone know of any existing standards for this? I'm setting up a scheme for my department, for AE projects we commonly use. As I templatize several processes I'd like to define a standard for layer label colors. As I was doing this it occurred to me that maybe there was a consistant standard out there worth looking for. I didn't find anything, hence this post.

I'd love to hear if anyone has a logical standard.

Thanks,
Matt