At my kids' dojang the color of the gi signifies which program you are in. For the regular class they have an all white gi. For black belt club it is all white with a black collar. Then there is a leadership class that grooms a select few to be leaders in the dojang, helping teach classes, running errands, doing the warm up, etc. and they wear blue with Leadership embroidered across the back. The assistant instructors wear a red gi. SabumNim wears a black gi and so does KwanJaNim. (sp?) Those are the 2 head, master instructors.
My son made this for me: