You can't change it from the one you pick at level 35, if that's what you mean. You can go back 5 levels and pick a different color if you don't like it (but you will also get the chance to grow other Kaos later)
Adding to ロウ (Row), you can jump back five levels, and change the color or whatever the choice was, but they’re all great and it won’t matter that much in the end, because after you finish, you get to start a new one. You can also, instead of jumping back five levels, jump back all the way to the beginning g again and start with either a Kao or a Student.
