Katie and the Sunflowers by James Mayhew

One of the most well written and engaging in the entire series. There is a bit of overtly intentional mess creation in it, but (as always) Katie is careful to go back over her tracks and make sure everything is scrupulously put right, so I'm comfortable with how it all works out in the end. There are always artistic renderings of lots of other famous pieces on each page, but following is a list of the works specifically explored:

Sunflowers by Vincent van Gogh
Breton Girls Dancing by Paul Gauguin
Apples and Oranges by Paul Cezanne
Tahitian Pastorals by Paul Gauguin 

As aforementioned, this is one of the liveliest Katie books and we ended up really enjoying it and getting entirely invested in the story. It's tremendously vivid and colorful, too! In the recommendation line up, would probably place it just after Katie and the Mona Lisa and Katie and the Starry Sky.

(Note: I just remembered that one of the imitation paintings on page 5 does show a nude swimmer from the back, but it can easily be covered, if you so wish.)