What would you think of derailleurs in colors like blue, red, green or orange?

It's been done. Ofmega plastic derailleurs and matching down-tube shift levers were offered in maybe five colors.

Here are three examples. From this page:

Just highly polished aluminum alloy for me, please.

No Sir... Polished or Chromed Aluminum is it...

And write me down for negative on the black ones too!

Same. Black bike components should be a crime in all 50 states.

Voted yes.

Not a flat matte coated but anodized colors would be good for me. Red, blue, gold, green, etc.

Also lodging my vote against plastic bike parts.

It isn't really a yes or no question.

More like "I suppose I don't really see any harm in their existence but I can't envision having one on any bike I would own"

No need. The market spoke 40 years ago.

I wonder how many of the Puritans voting silver compulsory/colors forbidden here were riding high-end racing bikes in the mid-1980's and lusted after/bought dark-anodized rims. And gold MAFAC brakes. And gold or black Fiamme stems and handlebars.

Or, if they were a bit younger, gazed longingly at the Campagnolo BMX cranks in the bike shop showcase, in gold, red, and blue.

Or kept their MTBs festooned with purple and pink Ringle parts.

I was. Dark rims? Sure. Not a “component” in my book. Gold brakes, stems, bars, chains?

Please.

I cannot see the derailleurs as I ride so their color is someone else's problem (and that person is behind me). That said, I rarely buy new components so I am usually picking the best odf what I see out there and that is almost entirely silver or black. (And after the normal nicks, etc, silver usually looks a lot better.)

Meh, if someone wants to color that part there are derailleur pulleys they can get.

I think they can look cool and often look gimmicky.
I also think you will never actually sell the mythical hybrid you have been working to crowdsource spec for years now.

Yeah, but my brain is really random. I like seeing all the positive comments for silver though. And I agree with the anodized idea. Hey, at the time of this post, there are 40% yes. I didn't expect that.

Save for the NOS Simplex derailleur I have ratholed away for a project, I don't have in a interest in plastic derailleurs either. But additives have improved the strength and UV resistance in resins a great deal. Injection molding would seem to me to be possibly cheaper to make derailleur parts from than die casting and machining for Walmart and big box store type bikes. The color options plastic would give would appeal to kids. The bikes would still be low quality with short lives, but the derailleurs are usually not the weakest parts of these bikes anyway.

I already have several bicycles with plastic rear derailleurs. They also have plastic crank arms. And lots of other bits and pieces made of "plastic".

In case you didn't guess, "plastic" is not a good way to describe something. Different plastics have very different properties. Some are very good for making high end bicycle components.

Almost all of the bottle cages on my bicycles are "plastic" with most being some kind of nylon. Much better than the old aluminum cages and much cheaper and better than a titanium cage.

Technology has progressed a long ways from hand forged steel. It will continue to progress for the foreseeable future. Get over it.

And for the record, I don't care what my bike components are made of or what color they are. Cost effective performance is what matters.

Oh, next on my upgrade list is a CarbonTi chain ring. Not cost effective, but really good.

No because they are unnecessary

Darkm rims, couche dure was a hard anodizing process by mavic used from 1985 till 2007/2008, which was made of ceramic and applied on the braking surfaces and the rim, it had a thickness of 50µ and a hardness of 600 vickers.It made many mavic rims more resistant and reliable than many of their competitors.
Gold plated groupsets were part of campagnolo's history and exclusively found the record groupset as seen in the links :
Rossin Record Gold Plated Spectacular Road Bicycle ,
ICS - ITAL CICLI SYSTEMS - EXCLUSIVE BIKE - GOLD PLATED CAMPAGNOLO C RECORD ,
Vintage Bicycle Feature: Gardin. Canada, 1983. ,
Colnago C35 Ferrari Gold Collectible Road Bike

It'll just be a niche market. So some small time business might be able to take advantage of that. But the big brands know for the moment what the most people will buy. Making variety of colors and finishes adds to costs that won't be made up in sales for them.

I have no doubt that bike would have impressed us if we saw it at Interbike. Obviously because of its unique-ness. Certainly not as a racing bike. I appreciate the number of quality photos included.

No. Adds too much weight.

It's not for me, but, you do you and enjoy the ride and don't worry what people think.

As those who have been offended by beheld my bicycles have observed, if I want to make something colorful, I can.

One data point: I placed colorful reflective sheeting on a good but not phenomenally fancy rear derailleur, but then changed my mind and donated it at the local co-op. It got sold notably faster than its blander brethren. But there is also the possibility of fast market saturation if more colorful parts hit the market.

45 years ago, colorful anodized parts ruled BMX. And many of the parts were identical to those used on road bikes, most notably the cranks and hubs. And now, a plain version of those parts will likely languish in a bin, while the colorful anodized version sells for stratospheric prices on online auction sites.

SRAM made derailers and shifters in a lot of different colors back in the 9 speed days. They were XO level and came in red, blue, gold, green, and pink. There may have been others but those are what I’ve seen. I own a red and green one as well as the matching shifters. I’ve repurposed the shift levers to match my Dean’s color scheme of red, blue, yellow and green. This is repeated throughout my bike.