I recently bought and finished the Legends ODA Warrant officer and Weapons sergeant. I didn't think I would be able to paint UCP convincingly, so I chose to portray them as wearing DCUs and plain vests/chest rigs. I painted the base colours with Vallejo and Tamiya acrylics, and the weathering was done with oils, acrylics and AK washes.
Unfortunately, the photos make them seem somewhat washed out, but the colours are actually more distinct in reality.
Comments welcome
Anirudh