I would side with those anxious for more variety becoming available in knife handles. Unlike the majority here, apparently, for the most part, I find FRN black to be more attractive than the typical textured G -10 handles. They almost instantly acquire a dusty, not-clean look, and spend the majority of their existence looking ugly, IMO.
Thanfully, since CRKT was the primary manufacturer of the first "good" knives I bought, they seem to like gray -- well at least a dark charcoal gray. I still think that aluminum handled anodized charcoal are very attractive.
I know little about the manufacturing processes of FRN, G-10, and micarta, but have a strong suspicion they can be made in any color of the rainbow. I've tried to make a case with SPyderco on their forum that lagging sales of the Calypso Jr are likely due to the "party-time" sounding name, and only black handles available. If any knife name cries out for a bunch of colors -- IMO -- that name is Calypso. We know from present and past Spyderco offerings that red, blue, pink, orange, and at least yellow are possible, in addition to black and gray. (Well, not sure of SPyderco gray)
Anodizing aluminum and titanium handles opens up a world of color possibilities. The world of stabilized and died wood, in addition to nature's colors, offers a plethora of color. Pearl, to me, is absolutely gorgeous. I think it is because I grew up thinking abalone shells were beautiful -- even if not ashtrays -- and that abalone was one of the best foods available.
I think the manufacturers are primarily to blame for the concentration of black. I think that by and large they've shown an unwillingness to experiment much. When they do some experimentation, they don't advertise it very heavily, excepting Gigand and the Fred Carter Titans. But then too, it may be us customers. Maybe sales of knives with handles other than black or SS simply haven't sold well. Even if there is a turdish quality about bead blasted titanium, at least it is gray!
Hell, I think that knives made with titanium blades, excepting military tacticals, should have the blades anodized the entire spectrum of colors. Just imagine a TNT with a turquoise blue blade, fading to gold at the point, and plum and gold blended handles. If nothing else, if such a knife were pulled in a live or die situation, if the BG laughed at the colors or combinations of them, he can at least die with a smile on his lips, as you strike ferociously while he's distracted.
I don't know why some outfit, like Gigand, doesn't offer a knife with scales in all the colors they presently use. You could carry a different colored knife every day, without the strain on the budget that would ordinarily entail. They provide wrenches with some of their models, I don't know about the Titan. Gerber has a natural for multiple scale colors, the Chameleon.
It is true that the darker knives aren't as obtrusive when clipped to one's pocket. Then again, all knives could use the SERE 2K clip, that leaves virtually no knife showing at all. I really long for the late 60s and 70s, with the sense of color and life that was so prevalent then.