A recreation of what I think the logo may have looked like - Funnyrikochet96726
Caillou is a PBS kids show that ran from 1997 to 2010. However, it has been rumored that there was a redub of the show which was mostly the same but with Caillou's name being replaced with Charlie titled Charlie, which is said to have been available on the XFINITY On Demand service in 2010. No evidence can support this, however. There is a lost Media forums thread about this and LSSQ made a video that mentioned about the supposed redub.
9 Pieces of Lost Media from Children's Television (Nick Jr., Playhouse Disney, PBS Kids)
LSSQ's video that mentions about the redub. (15:32)