Anodization in color never works as the control of temp, voltage, stirring, mixture ratio, quality of surface, grounding, etc...all of that is never exactly repeatable.
thus, two functional anodization colors, silver and black. for black, it's easy. Check it and let it sit longer if it is not black enough. Silver, much the same.
Painted colors, susceptible to the materials underneath not being clean enough, chipping, scratching, cracking, mismatch of colors, and so on.
OK for speakers which sit alone, but the anodization can be a pain due to lets say three pieces, bought and made at different times, each having three different anodization batchings, and thus, all different looking.
Importantly, ...Dye.
Black is a opaque pigment when anodizing..for the most part... colors are transparent dyes, for the most part. Thus susceptible to light based fading. Sometimes they fade all on their own.
Most chassis makers for audio companies will only reasonably try to talk their customers away from messing with the mess of the idea of anodized colors. They will do it, but they will not guarantee anything for you.
Period. You are on your own, if as a manufacturer, you decide to try a batch of anodized colors. As anodized colors are just.....crap.
So, basic black, just leave it in the bath long enough and it comes out black. Tough to screw up, easy to match up with another face-plate done at another time by another company. Silver, just clean anodization, perfect match.
Thus the existence of the nearly ubiquitous two: Black and Silver.
