The only equipment that has the color buttons tends to be hi-def players, and even they don't seem to use them much. I can see where you'd want them handy if they were important buttons for your TV tuner navigation, so your solution looks great. It'd be nice if an NSP update added an option to just select background colors for those button labels.

I put text on the hard buttons. The left button is almost always "Devices" taking you to a device selection page so you can quickly get to the controls for a specific component if need be, and the right button is almost always "TV Adj" to be able to quickly tweak display settings. These could, of course, be integrated into device pages in other ways, but I find this pretty handy.