An iMac owner sued Apple on Monday claiming the 20-inch iMac desktop computers can't display the "millions of colors" Apple promises in promotional materials. The Cupertino-based company touts that ability on its Web site and other marketing material even though it knows iMac monitors can display only 262,144 true colors, according to the lawsuit, filed in U.S. District Court for the Northern District of California. Users are fooled into seeing many more colors because the monitors use technological tricks that involve showing many similar shades at high speeds to create the illusion of the desired shade, according to the lawsuit. Those techniques can cause "crippling" problems for people editing pictures and videos because the colors don't always appear entirely smooth, the lawsuit said. The plaintiff, Texas resident and iMac owner Chandra Sanders, is seeking class-action status for the lawsuit. The lawsuit targets the 20-inch "Aluminum iMacs" introduced in August 2007. Apple said it doesn't comment on pending litigation.