It is for the teams that have the shirt number with 2 or 3 colors, in the table kits there are 18 tables referring to the shirt and trouser numbers. They are:
Those are the 3 boxes that I told you.
For example: FIFA numbers are usually in Red (R) but there are also some that have details in Green (G) and Blue (
, then I leave you an image of how CG File Explorer is made.
Here we would need 2 boxes, one to edit the color R and another to edit the color G, and other from color B.
I'm bad with explanations, sorry haha.