Yeslevels will do the job (but I prefer curves)
(
Duncan Disorderly,
Mon 31 Mar 2003, 23:01,
archived)
curves are good for coloursbut for this specific job levels are better suited i think. (pretends to know what he's talking about)
(
Professor Fnord Regius Professor of B3ta Chronology,
Mon 31 Mar 2003, 23:04,
archived)