Duckie hurries across paper collage scenes on double-paged spreads of supersaturated color, each one smaller than the last. When opened, each set of pages forms a half-round of extra-heavy card stock, backgrounds awash in the stated color. Duckie starts out in a red poppy field, and “hopped under the orange bridge . . . and waddled around the yellow cornfield.” After the green tree and the blue pond, she gets caught in an indigo shower that gives way to a brilliant rainbow on the final opening, thanks to the increasingly smaller pages. Young viewers will be drawn to the quarter-circle shaped cover, and mesmerized by the hues within this dazzling prelude to Lois Ehlert’s “Rainbow” titles. Fans of The Very Hungry Caterpillar will be pleased, too. A bright and appealing debut for the diaper set. (Picture book. 3-6)