not the author but afaiu r3 uses the "color" concept: tokens are tagged by type via 8bits (number literal, string, word call, word address, base word, …) and

not the author but afaiu r3 uses the "color" concept: tokens are tagged by type via 8bits (number literal, string, word call, word address, base word, …) and the interpreter dispatches using these bits it just doesn't use the colors visually in the editor and uses prefixes instead (" for string, : for code definition, ' for address of a word, …) which also means the representation in the editor matches that of the r3 source in files.