Books about colours - we can often find board books of colours. I liked the simplicity of Tana Hoban books which are often to be found second hand The child has an unconscious absorbent mind at this age. So we don’t need to “teach” colours.
Tana Hoban was the ground breaker for black and white texts, but her's are not my favorites. This book I did like as a color book. Each page shows a photograph of an object that is one color. I particularly liked that kitten and bunny.