Is it? I'm not trying to be argumentative, but I have never seen a "standard" colour belt system with requirements from the KKW. In my case, my first school required taegeuks 1 & 2 to obtain a yellow belt, whilst the next school required a "basic" pattern (taegeuk1 is taught at the yellow belt level).
You are correct. The KKW actually only defines standard requirements for Dan ranks.
However, given that 1st Dan requires the 8 taegeuk poomsae, then it's pretty easy to divide them up amoung 10 geup ranks (or 5 belts, in the system Manny proposes). And it's still pretty difficult to imagine needing a year to learn the most basic material.