Charles Moore did that with Color Forth and even though only he was using it, I remember several comments on how that is unfair to the color blind or visually impaired which is an interesting point.
ColorForth has a color-blind mode, but I do not remember the details.
The main idea is to change visual representation instead of using delimiters. Different fonts or text sizes sizes or cursive/inverse/underline are also valid ways of displaying different "colors".
The main idea is to change visual representation instead of using delimiters. Different fonts or text sizes sizes or cursive/inverse/underline are also valid ways of displaying different "colors".