Fiewfox, Thank you for all this!
I think they look great. I'd buy a red and a full black set of buttons, and most likely a blue set.
Now, as to the fedback you asked, I think it would be best to match the lens color you mentioned, so I'd vote for that. Also, as I said in the other thread, maybe rather than a black set of buttons you may consider a "gray" set of buttons, same color as the fascia (plastic part arount the lens), so that the buttons are "stealth". I think that's a nice solutions for those who can't find a color that matches well the instrumentation or the interiors.
Just my 5 cents, hoping they're useful. I'd probably buy all the colors just as they are now!