I'd appreciate dropping red/green as bad/good colorscheme. red & green feed one of the most common visual impairments, and tend to work quite bad with terminal fg/bg colors throughout the spectrum except for its ends (black & white). Maybe you have some color profile descriptor somewhere that a user can change, but a quick search through info gcc (of my installed version) just shows the ability to turn it on & off (-fdiagnostics-color=[auto|never|always]).
Color is definitely one of the things that do NOT work well on a wide variety of terminals. try a white-on-firebrick VTE, or a black-on-darkgoldenrod (awesome for sun-glare, btw), white-on-green, white-on-purple for a change to see how well they mingle...