I've made kits for fifa2000 and fed2000 does not do it.
You need a utility like EA Graphic Editor or Sonique. Get them from the downloads section.
You will now be able to open and edit a varitey of graphic files in fifa2000.
I would tell you more about how to make the kits but I'm really tired and can't think straight. But have a go, I do know it can be fustrating.
Download my kits from http://galah.4t.com
and you can muck around with them if you wish. It is the best way to learn. Note the three colours, red, grey and blue and how they are changable in the game.
I'm off to bed. Hope this helped.