In this page i will describe Krillin's costumes.
Krillen wears this Gi during some of Dragonball. It contains an inner yellow turst the ends like a t shirt at the arms. over this he has an orange shirt on the raps over his chest, covering his front and back. This part ends just below the waste and is held to him by a black belt. He wears red pants that ends with yellow on the very bottom. And last he wears brown boots.
When Krillin is accepted as a student of Master Roshi and starts his training, he changes to this outfit. Like most of Roshi's students, they keep it and slightly modify it long after they leave his training. Krillin continues to wear this outfit until he goes to Namek, and then after that seems to only put it back on if he plans to get involved in a fight.
This armor is given to him by Vegeta on Namek. This is pretty much the same as the one Vegeta wore on his arrival to Earth except for color and the groin area. This armor is black and yellowish gold with black in the center. a black body suit is also worn with this, also different from Vegetas, Krillens are shorts and the arm length is to the elbow. White gloves are worn along with boots which the same yellow color as the armor and white. Event though Vegeta did him a favor, Krillen has to complain about how Vegetas looks much more stylish and maneuverable.
When Krillin starts to grow his hair and settle down and have a family, he wears this outfit. It's casual, not meant for fighting (showing he's pretty much quit at trying to become a stronger fighter), and he continues to wear until the end of the Buu Saga.