Use color capabilities of the terminal #1
Description
(Inspired by blefloch/latex-unravel#3.) Many terminals are able to display colors using various escape sequences. E.g.,
pdftex -8bit '\message{normal\pdfunescapehex{1B5B}1;9;34mFANCY\pdfunescapehex{1B5B}mnormal}'
writes 'normalFANCYnormal' with 'FANCY' in color (and bold and strike-out). Using colors could be useful to distinguish various kinds of words in Forth for instance.