The TMP uniforms are actually a lot more practical and believable as real clothing. Add a bit more color and I think they'd work great. And while the colors are understated, they're not really as drab as people think. The problem is that the process used to transfer film to video in the '80s washed out the colors, so a generation grew up seeing a blander version of the film than the one that debuted in theaters in 1979. Also, even on the Director's Edition with the colors restored to their original vividness, the bridge scenes still have more subdued colors due to the dim lighting that was used to ensure that the filmstrips in the "monitors" would be visible. You can tell that Spock's uniform, for instance, looks gray on the bridge but blue-gray everywhere else.