These are the display colors in RGB.  The game is actually displaying extended ASCII characters in OpenGL, so you can modify the colors.

[BLACK_R:0]
[BLACK_G:0]
[BLACK_B:0]
[BLUE_R:34]
[BLUE_G:79]
[BLUE_B:170]
[GREEN_R:79]
[GREEN_G:170]
[GREEN_B:56]
[CYAN_R:56]
[CYAN_G:136]
[CYAN_B:170]
[RED_R:170]
[RED_G:0]
[RED_B:0]
[MAGENTA_R:170]
[MAGENTA_G:56]
[MAGENTA_B:136]
[BROWN_R:120]
[BROWN_G:94]
[BROWN_B:47]
[LGRAY_R:192]
[LGRAY_G:192]
[LGRAY_B:192]
[DGRAY_R:128]
[DGRAY_G:128]
[DGRAY_B:128]
[LBLUE_R:63]
[LBLUE_G:127]
[LBLUE_B:255]
[LGREEN_R:127]
[LGREEN_G:255]
[LGREEN_B:84]
[LCYAN_R:84]
[LCYAN_G:212]
[LCYAN_B:255]
[LRED_R:255]
[LRED_G:0]
[LRED_B:0]
[LMAGENTA_R:255]
[LMAGENTA_G:84]
[LMAGENTA_B:212]
[YELLOW_R:255]
[YELLOW_G:255]
[YELLOW_B:84]
[WHITE_R:255]
[WHITE_G:255]
[WHITE_B:255]