Usable is in the eye of the beholder.
64 colors is the absolute maximum if sluggish displays bother a person regardless of CPU being used. To each their own, but I don't know how novacoder can stand that sort of performance. It drives me batty.
Other than sluggish displays though, chipram is a big consideration. 128/256 colors puts a serious dampener on amount of screens concurrently usable, along with their resolutions and color depths. And yes, this is even with fblit, ftext, cyberbugfix, etc. Installed.
And really, a well constructed palette, especially at higher resolutions, makes a massive difference. 16 colors is maybe a couple too few, so dithering, etc. will always be apparent, but up that to 32colors, or 64 and some creativity, time and effort can result in a desktop that looks as nice as anything out there.
