There are only a handful Kulilin was seen in Dragonball dressing up and much more wear a cap to hide his skinned head.
Here's Kulilin in casual wear before heading off with Bulma and Gohan to planet Nemak.
Although his attire is casual, there are some details that make you think twice. His casual attire are basically customized!
First he wore a baseball cap that has his name on it.
Second his jacket has a "Turtle" clan logo of which he is apart of.
Now unless he tailor made it if not he would have to pay more to get it customized.
It's not everyday you see people wearing orange shoes. Hehehe
So that is Uncle Kulilin dressing casual smart for his mission to Nemak. Being an uncle, Kulilin have to show more confidence and to take care of the young Gohan
But nothing will prepare him to leave in the same spaceship with Bulma that will eventually giving a hard time because of her mood swing and her living hygiene...
None of them actually have even an ideal of the things to come.
Sometime ignorance is bliss. Don't you agree?