[Coco] Basic Colors with RGB monitors Coco3 real or emulated

[Robert Gault]

Given the recent spate of messages about incorrect colors on RGB monitors, don't 
forget about the following.

Tandy in its wisdom or lack of, set the default colors to CMP. After a cold boot 
with an RGB monitor, Basic will require the RGB command on a Coco3 to get 
correct colors. That applies to MESS and VCC even after setting the emulator to 
RGB video mode.

This does not apply to MESS in a Coco or Coco2 mode where only the emulator 
needs to be set for RGB.

Robert