Babies spend a lot of time staring at things. As their vision develops, newborns like to look at contrasting colors and shapes. The pictures in many children's books have strong color contrast to aid in this development. Your baby will enjoy gazing at them. Prop open a book with a bright illustration at the side of your baby's bed. They will enjoy the picture!
These books have bold illustrations which babies will enjoy:
Machines at Work, Picture Book by Byron Barton
My Car, Board Book by Byron Barton
Red Leaf, Yellow Leaf, Picture Book by Lois Ehlert
"More More More", Said The Baby, Picture Book by Vera B. Williams
Red, Blue, Yellow Shoe, Board Book by Tana Hoban