Even after the Notepad poured black paint over the Yellow Puppet's clown painting, someone still appreciated the work the Yellow Puppet put into the ruined picture enough to frame and hang it up in the puppet's living room.
What are the puppet's favorite colors? The Red Puppet likes blue, the Green Puppet favors red, and the Yellow Puppet prefers green. In other words, their favorite colors are each other's hair (or feather) colors.
On one of the photos on the wall, the one representing the past has the three friends outside their house smiling at the camera. They clearly care about each other at least somewhat.
Despite how unsettling and strange Manny's dad, Roy, is, Manny still likes him and considers him a friend.
The fanon idea that Roy was the in-universe source of the 96,000 pounds out of concern for his son.
The fact that some of the DHMIS Kickstarter reward options include a drawing from Yellow Guy. It's nice to see that he's still being creative after Sketchbook's repeated insults.
Fandom example: On July 16th, 2014, someone entered a DHMIS Flock Draw room and started messing up the drawings. A few hours later, the person and the fans got to talking, and it turned out that the apparent troll had never even heard of DHMIS and just wanted to have fun with the Flock Draw. Long story short, by the end of the day, the fans and the person were drawing together, and the person was made an honourary DHMIS character.