My little guy’s room doesn’t have a theme per se, but if I had to name one it’d be Richard Scarry. I love Richard Scarry dearly — revisiting all his books I can see he built the foundations of my tastes in art and design. So I will impose him on my son until he requests something else (but so far he loves it — you pretty much can’t go wrong with cars that are also other things).
I bought this sheet from eBay a couple years go. I love how of all things you could include for the letter C, he (or the textile designer) chose “crocus” and “chicory.” These sheets are rare as far as vintage kids’ sheets go, so if you want one, I recommend setting an email alert for yourself.