The word decolourizes is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 27
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (49 words)
ceroids, closure, colours, coolers, coulees, coursed, creoles, creosol, croodle, cruised, curdles, deciles, decolor, decries, deicers, delouse, diocese, doozies, duelers, eluders, leisure, lousier, odorize, oilseed, orioles, reclose, recluse, recodes, recoils, recused, reduces, reoiled, rescued, residue, resized, reslice, resoled, scolder, scoured, seclude, secured, seducer, seizure, sluiced, sluicer, soldier, sourced, ulcered, zeroise