I've always given my villagers 'uniforms' as well. For VV5, I always train children to "trainee" in the first 4 skills then dress them in green and have them all farm. When they've mastered farming, I dress them in blue and have them build, after mastering building they're put in red and dropped into the research lab. (I do this order because they get slower as they get older, so I want to get farming and building done while they're young.)

When they've mastered the sciences they become "Esteemed Elders" and get a greyish robe to study medicine in. If they master Medicine, they get another uniform to show that they've mastered 4 skills and then I set them to Devotion in hopes that they'll learn (most do not, but some will). If they master 5 skills then they get white robes and the few that master all 6 get yellow (the same colour I dress all the children in). This way, when they die, I know by what they're wearing how many skills they mastered.