The problem with the aesthetics of a great deal of technology is that they are usually designed to draw attention to the device, when they should be designed not to draw attention. Undoubtedly the single biggest example of that is gloss. Especially dark glossy finishes, while effective at marketing, are not an option for practical use. It's much worse again when you are left without the choice of matte finishing (case in point: video game systems).
After that, there's the whole light vs. dark casing thing. While dark shades are more marketable, lighter ones downplay the effect of shining and therefore may well be more pleasant to actually have. The only disadvantages are that discolouration and dirt are more visible on light surfaces, but you can't have it all.
Of course, I don't mean as close to white as you can manage, subtlety being the key theme after all. Just a fairly light grey.
And of course there's the matter of LEDs. As I'm sure you all know, high-intensity clear types are all the rage these days, even in places they don't belong. The only LEDs that should be used as indicators are low-intensity diffused types, with one exception - for a warning indicator, a brighter LED may be desirable. Still diffused, though. As for colours, for the PC case I prefer green for power and orange or red for HDD activity. For video displays, the power/standby indicator if present should be off with the display active, so as not to be a potential distraction.
As odd as it is to admit it, I have power cords of all things that have better aesthetics than many high-tech devices.