Yeah I totally agree, subtlety is the name of the game here. I think mainboard manufacturers are starting to move toward that direction. In general, RGB LEDs just make it easier to choose exactly the colour you want and change that in the future without replacing LEDs, so they offer a lot of value over regular single-colour LEDs.
The second thing that has to change is the existence of a myriad of in-house, non-documented lighting protocols. ASUS, MSI, Cooler Master, Thermaltake, Corsair, Razer, Roccat, Alienware, everyone and their dog have custom software for controlling lighting on their products, and most of them integrate into obnoxiously large software suites that take minutes to load, slow down your boot time and look horrific in general.
Lighting in PC parts an peripherals has to be seen as a separate entity from the product itself. An advent of an open standard would greatly simplify this sort of thing, but I don't claim I would know how to implement such a thing, and it would be a lot of work to write a piece of simple software that retroactively included all or even just the most popular of RGB lit (cue air horns) product lines.
