In this imaginative book, Eric Carle invites young readers to discover complementary colors while enjoying the amusing story of Little Frog and his colorful friends. It’s Little Frog’s birthday, and Mama Frog gets a big surprise when the guests show up for his party—all the animals are the wrong color! Little Frog tells her she’s not looking long enough, and he’s right. Goethe (1749-1832) is celebrated as a great German poet, novelist, and philosopher. But in his eyes, color theory was his most significant achievement. In 1810 Goethe published Farbenlehre , naming three primary colors--red, blue, and yellow--from which all other colors could be made, and claiming that each color had an opposite, or complementary, color. But how does this relate to well-loved artist Eric Carle's Hello, Red Fox ? Well, it's like this. On his special birthday, Little Frog's friends--Red Fox, Purple Butterfly, Orange Cat, and others--begin to arrive at his house for a party. Imagine Mama Frog's surprise when she perceives Red Fox as green, Purple Butterfly as yellow, and so on. Each time, Little Frog gently points out that she simply hasn't stared at each animal long enough to see his or her "true color." At the beginning of the book, readers are instructed to stare for ten seconds at the boldly colored animal on the left side of the spread, then transfer their unblinking gaze (more like glaze at this point) to the blank white page on the right. If they do that successfully, a shadowy image of the animal appears in its complementary color! Young kids may think this is magic, but actually the phenomenon taking place between the eye and the brain is called "simultaneous contrast after-image." No matter what you call it, it's amazing and fun to behold! The story itself is simple and deliberately repetitive, appealing to very young children, but the optical illusions will be a hit with all ages. Carle's bold collage illustrations are perfect for this playful spin around the color wheel, which ends with the green Little Frog turning red when Mama Frog kisses him in front of all of his friends. (Ages 4 to 8). Karin Snelson PreSchool-Grade 6AAn introduction to the concept of complementary or opposite colors, cloaked in a story of a birthday party. Little Frog describes his animal guests to his mother, but none of them seem to be the color he attributes to themAuntil readers stare at each of them for 10 seconds and then look at the pure-white facing page for 3 seconds. Then, Red Fox, seen as green in the large, clear illustration against a stark white background, appears red. Orange Cat, depicted as blue on the left, turns the appropriate color when the same procedure is followed. The problem is that the mechanics required to illustrate the principle and make the story work are too burdensome for preschoolers. Even older children may not have the patience or interest to sit still and repeat the necessary visual exercise all nine times it takes to complete the story, and the thin plot will hold little interest for them. Carle's many fans will no doubt pick up this book, but they are likely to tire of it quickly.ADiane Janoff Queens Borough Public Library, NY Copyright 1998 Reed Business Information, Inc. Ages 5^-8. Before the story begins, readers are instructed to stare at a dot inside a red heart for 10 seconds, then transfer their gaze to the opposite blank page. On that empty page, the heart shape reappears, but it is green, the opposite or complementary color. The very slight story is really just a reason to explore this phenomenon. Little Frog invites Red Fox, Purple Butterfly, Orange Cat, and others to his birthday party, but when they arrive, Mama Frog observes that the fox is green, not red, and the butterfly is yellow, not purple, and so on. In each case, Little Frog instructs his mother to examine the image of the animal, then look at the blank opposite page where the guest appears in the true color. The required "looking" time disrupts the flow of the story, but as an experiment, it is great fun. Facing the title page, there's a brief history and explanation of Goethe's Farbenlehre, or color theory, but curious children will want to know more than the information provided. A playful starting point for science discussions at home or at school, this is sure to intrigue children. Linda Perkins Carle (From Head to Toe, 1997) asks readers to engage in optical illusions to view his illustrations for a story that becomes an unforgettable lesson in complementary colors. By staring at a picture--e.g., the green fox on the cover- -for ten seconds or longer, and then looking at a blank page, the picture reappears, in this case, the red fox of the title. The end papers feature helpful color circles so readers can locate colors and thus their complements. The story is minimal: As the animal guests arrive at Little Frog's birthday party, they appear to Mama Frog to be the wrong color--for example, Yellow Bird is purple--until Littl