The word chromoplast 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: 23
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (33 words)
amorphs, cahoots, caltrop, camphor, captors, carhops, carpool, chorals, clamors, cohorts, compart, comport, compost, harlots, locator, moolahs, mortals, ooplasm, ooplast, patrols, poromas, portals, prosoma, scholar, scotoma, scrotal, shampoo, splatch, splotch, stomach, stromal, taproom, toparch