change the default colors a bit based on color-blindness feedback
change the default colors a bit based on color-blindness feedback

- paren color from brown to a neon blue
- string and number constants from green to a bright purple
- lighten the comment color

the basic problem is to try to keep the red error color very distinct
from the others and try to keep the others distinct from each other
(but that's less important)

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket