I tried "art with the theme of joy" in an Ecosia search and got a variety of results that looked decent. A search like that should be a good starting point. Take note of the artists that have used that theme and see what else they do. You could follow up by searching for books about what you find. Also, look on art gallery websites etc for what exhibitions are or have been that may cover your theme.
Do you have a local art group (even for people who get together to make art) and ask them?
Never mind, it didn't really matter...