If you want to set the screen color to something other than the few that have names (i.e. Amber)
then you need to be able to disable the automatic addition of NOSCROLL to OPTION LCDPANEL CONSOLE. To add the PicoCalc LCD controller, make this fix to MM_Misc.c, line 5425:
if (!(Option.DISPLAY_TYPE == ST7365P || Option.DISPLAY_TYPE == ST7789B || Option.DISPLAY_TYPE == ILI9488 || Option.DISPLAY_TYPE == ST7796SP || Option.DISPLAY_TYPE == ST7796S || Option.DISPLAY_TYPE == ILI9488P || Option.DISPLAY_TYPE == ILI9341 || Option.DISPLAY_TYPE >= VGADISPLAY))