My niece and I both loved Frederick! When Frederick was telling his siblings to close their eyes and imagine the sun and the colors, my niece took his suggestions to heart. We live in the grey Pacific Northwest, so we totally identified with what cloudy, colorless winters are like! With her eyes closed, a little smile came onto my niece's face and she said, "Mmmm... I *can* feel the sun! And the colors *are* beautiful!" We both smiled at the end of the story, and agreed that it's a pretty great book. Our environment may play a big role in our appreciation of Frederick, however.
My nephew didn't even listen to the story. But he did like the picture of the mouse tracks in the snow.