Is It Dark? Is It Light?

The hints are abundant, but subtle: moonlight shining through a windowpane, star-speckled wallpaper, a mobile of the solar system. Quick-witted readers will soon catch on to the fact that the ``it'' in this cleverly conceived and executed picture book is the moon. Meanwhile, a pair of children pose questions and answers about the moon, at the same time introducing the concept of opposites. (``Is it hot? No, it's cold.'' ``Is it little? No, it's big.'') Schuett's luminous paintings, rendered in the deep, velvety palette of an evening sky, wittily foreshadow the correct answer--the fullness of the moon is echoed in the roundness of a fried egg, a cake of soap, a balloon. The final page seems somewhat tacked on--multicultural children gaze up at the moon, while various translations (``luna,'' ``mond'') float overhead. Ages 3-7. (Aug.)