Silver is the appropriate color for everything but speakers.

I don’t know where it came from. Maybe back in the 70’s? But somewhere in my brain silver means "cheap" and black means "pricy" . I think the hi dollar audio shops that carried big names had black units, and all your Webcors, and Philco etc units sold at Buckeye Marts and Woolworths were silver. Kind of ruined it for me . Then in the 80’s all the rage was silver Marantz’s, Sony’s etc . We had to accept them as that’s the only way you could get them and then BAM, you had a choice. I’ll stick with black

I'm an Industrial Designer and I do appreciate a thoughtfully designed piece of audio gear. I generally prefer silver especially when there are polished edge chamfers and other fine details. 

I have often envisioned other materials and finishes that I think would be fantastic for audio designs. One that comes to mind is glass. There are challenges but, I think glass is underutilized. I can visualize a soft matte texture on the backside of a 1/4" thick glass panel that is back or edge lit with a tasteful glow across the surface. The lettering could be cut into the backside and when lit from below these details could stand out like a piece of Steuben glass. Glass can be shaped and formed. 

My Abel fly reels also have some fantastic anodized finishes that I think would apply to audio gear. I have seen some clear finishes over aluminum, with a slight hint of color, that would give a beautiful tinted look to the silver- like silver teal or smoked aluminum....

Not much risk-taking going on in audio gear design. 

i know silver is a classic 80’s color, but I much prefer black. Black is elegant and timeless...unless it’s piano black, in which case it can look cheap if it’s not done well.

Add a bit of chrome if tubes are involved....maybe a champagne gold if you want to do the retro thing, but silver is all kinds of meh.

I believe it was Henry Ford, who said you can have any color you want as long as it is black.  Black lacquer dried the fastest.  He did make Model T's in other colors.  Digital Amplifier Company gives you a choice on some models, a red or black faceplate.  My Maraschinos only come with a red faceplate, the power supply is red also.  I really don't care what the faceplate color is, it is under the hood that counts.  I have several Meridian pre/pros they have a glass like top, actually it is persplex a type of acrylic.