The book version (without music) of the musical production that began in Britain as a 15-minute school ""entertainment"" and hit Broadway early this year. If this hasn't the vigor of a live production, Quentin Blake's scraggly, energetic, hammy pictures contribute a zest of their own that is sportively in tune with the words. The rainbow never saw all the colors Rice and Webber haul out to describe Joseph's wonderful coat, which was ""In a class above all the rest/ It even went well with his vest."" But as for the brothers, an unshaven, disreputable lot in Quentin Blake's cartoons, "". . . now this coat/ Had got their goat."" The dreams of course were a further goad: ""The accuracy of the dreams the brothers did not know/ But one thing they were sure about--the dreamer had to go."" And so their ""repulsive crime."" (And oh, those evil leers Blake gives them!) ""Oh those brothers, how low could they stoop?/ They made a sordid group, hey, how low could they stoop?/ Poor Joseph, sold to be a slave/ Situation's grave, hey, sold to be a slave."" As the adventure proceeds, sometimes with lapses into play form, you don't forget that this is just a transposed script--but a group could turn that to advantage. And though the many refrains unquestionably call for music, that too is available on record. As for the book alone, at the very least it's a zippy way to get through the Bible story.