Painter’s Servant Junior/Lite/decaf
Shifting Sky is a less-broken (and not banned in Commander) version of Painter’s Servant. Where the Painter’s Servant affects all cards, spells, and permanents, Shifting Sky only affects non-land permanents. Common Cause works well for this, unless a land is animated, since it may then still be colorless.
Or, you could choose a color that you don’t have in your deck, so all of your non-land permanents gain that color. You know, if you want your creatures to be multicolor for some reason. Or maybe you just want them to be immune to Fear (by making them black) or Intimidate (since all creatures share a color). Ignore this bit, as it makes all permanents one color, but not in addition to their current. Rest of the article is legit though.
Or maybe you’re using it a bit more offensively, to make all permanents a certain color that your deck is built to have protection from. Your creatures have protection from Black, and since you chose to make everything Black your opponent can’t block your creatures, and when they attack you can block without your creatures taking damage.
Or maybe you just think that having something in common is a good way to find peace.
