I just wanted to post about this as well.
Currently, there is no way to get the right colors as advertised here.
But because this is the standard palette for all uniforms, I don't expect a fix.
We had the same problem with the Motion Picture uniforms, and Cryptic said that they have a long-term fix in the works, that surprisingly, doesn't offer us more colours, but rather offers us fewer colors, in "Canon" pallets related to each uniform. I'm not sure I like that approach. I'd be quite happy with a hexadecimal colour code field, and let the canon-obsessed people create guides to Canon colours if they want to.
Personally.. although it's not canon, I've really enjoyed seeing people "go wild" with the uniforms in STO.. and I think taking away player's opportunities for creativity would be a mistake. But then I felt the same way about them taking away custom beam colors.
and the KDF did get new uniforms they were just added in the game with no cost, the Orions and Nausicans for the longest time only had the option of wearing Klingon Uniforms. Then they added in the Klingon Chest Armor pieces as well.