So, I *hate* the clear/white flasher domes for Training on both ramps blasting me in the face when they come on in a dark room. So I tried all available colors: green, yellow, orange, red, purple, blue. All of them seemed wrong, except red, purple, and green.
Unfortunately, purple transmits too much light and looks blown-out when lit up. Red in that plastic standup looks like it should have always been that way, but the red flasher dome on the side near it makes it not great (too much red flasher in your sightline on both sides with red for training, too). After thinking red was "it" I changed to green after only a few games, because green breaks up the red flasher congestion on each side, and green means "go" universally. Also, in real life, the green is not as blown out when on as it is in this gif, I couldn't get my phone to iris down because it was flashing too fast.
After this test, I highly recommend green, followed by red dome "cap" inserts (note that the "cap" half domes have only one fastening tab, not two) instead of the too-bright and visually incongruent factory clear/white.
Here's a GIF of each "finalist" test...
Seriously, though, green or red are both better than clear/white cap dome. Changing yours out is in the top 3 best mods you can do for your TMNT.
Stern? It's not to late for a running change to green for these on the line...save America's eyes.