I recently noticed that the default background for Ubuntu 23.04 "Lunar Lobster" has a purple star missing and now that i noticed it, i can't unsee it. The one towards the bottom right is barely visible so that passes.
I didn't mean the official Ubuntu flavors, I meant 3rd party Ubuntu variants. Stuff like https://archiveos.org/ubuntu-satanic/ which is literally just about changing a few graphics.