The so-called "rainbow effect," consisting of brief, distracting red, green, and blue flashes in a projected image, is the bane of some projectors using Texas Instruments' DLP (Digital Light Processing) technology combined with a color wheel. Our projectors Lead Analyst, M. David Stone, will note this effect and its severity in his reviews of projectors that suffer from it, and perhaps lower their rating because of it. But a projector that "throws" only rainbows--well, that's a beast of a different spectrum. Rainbow in My Room, from science-toy manufacturer Uncle Milton Industries, is a novelty item for kids of all ages--or at least those 5 and up, according to the manufacturer's guidelines. It projects a rainbow on the wall and/or ceiling.

Rainbow in My Room is part of a toy series that also includes Robot in My Room, Moon in My Room, and Solar System in my Room. It requires 3 AA batteries, though an optional AC adapter is available. It is sold through various e-tailers for prices as low as $21.10 (Amazon). Shoppers seem to love it--it averages a 4-star rating in buyer reviews in the sites I've checked. So although we'll continue to give the "rainbow effect" a demerit when it appears in normal projectors, thanks to Uncle Milton it appears to have a (dare I say) bright side.