I dunno. Here's TCMD and the console after being detached.
With that prompt, I never see a green prompt in TCMD. I had done some testing and found that ^e[32;1m, ^e[92m, and ^e[38;2;0;255;0m all put that attribute 0x000A in the console screen buffer, read with either ReadConsoleOutput or ReadConsoleOutputAttribute (does TCMD use one of those?). I'll do those tests again.
Have you (or anyone else) tried ^e[38;2;0;255;0m?
As you might have guessed, it's not only the prompt. Whenever I use ^e[38;2;0;255;0m in TCMD I get the default foreground color.