At the same time there are software that don't work right on newer Macs.  I had problem playing Dragon Lair game on my Centris 610 unless I turned off the internal cache.  There was a freeware game, a overhead dungeon crawl (I can't remember) that worked fine on B&W mode but was behaving weirdly if you started in anything other than straight B&W and I could never get it to work on my Centris or Duo 280 at all even in B&W, maybe it had issues with '040 or was designed to exploit a 32-bit dirty system (16 or 24 bits only games) and '040 is only able to work as 32-bit clean.

Cogito doesn't like it if you switched the color setting while it's running, it just spits bad resolution and quits.