The Greencoat Militia or simple "Greencoats" are a volunteer force dedicated to the defense of any peaceful community that contributes to them within their sphere of influence. Whilst their equipment is often derided as "basic" compared to other outfits, they're training, logistics, and numerical superiority have made them a force to be reckoned with.
Whilst Fallout 4's Minutemen are great, I don't plan on setting my games in the Boston area per-se... despite the fact that I live there!
Thusly, I enjoyed painting mine with a green motif instead of blue. This also helps them blend into groups of my settlers as well.
My only regret is that I think I should have tried clipping some of the laser muskets into jury-rigged laser rifles... I'm just not a big fan of the extended muskets, especially the sniper musket of Preston Garvey. Oh well... maybe the next batch?