I had the idea of having 4 colored dots arranged in a square. Either by the side champion icons, or on the scoreboard. A pink, purple, red, and blue icon. I was also contemplating Elixir icons, but can't think of good justification.
The justification for the 4 indicators? While spectating a streamed match, when a fight happens, or a steal is attempted, it is hard to QUICKLY determine who has the buff. Also, while the game progresses and you want to figure out if the buff has worn off, or if when the jungler picks up the buff, or passes it off, etc...
To simplify my explanation, it's for keeping the spectators of streamed matches informed of what is going on off camera. And I feel a simple dot on the screen, next to the summoner/champion icon could make a huge impact.