Chris, thanks for the screen shot. My mistake, and now that I think about it I new it was there in the past but stopped using it and forgot about it. Here is why I stopped using it. When I go to edit materials with the color wheel. I see a point that represents the current color, and I can make minor adjustments. I found that the sliders don't update to the current color so was fine for new colors but not tweaking existing ones.
Looking at it now I see can choose Grayscale, RGB, CMYK, HSL sliders. Interesting next there is also a pulldown to choose a profile next to the slider, so If my photoshop document is AdobeRGB, I can choose adobe RGB profile before I enter color, and then if I switch to srgb. The color appearance won't change, but the numbers will. This is the first thing I've noticed in SketchUp that mentions color profiles.