This, so much this, what a fantastic idea.

I don't even know if four colors like a couple have suggested is necessary. Just three: aggro ping (for ganks, tower rushes, etc.), MIA ping, and danger ping (for if enemies might be approching, maybe other uses).

I do agree that at high level players should be map aware. But there is always that time when your busy, would it be for 3 sec, and you can miss something and die. MIA calls are always a plus but deffinilty if its going to be pinged, it needs a different color and sound.

I hate people pinging their lane so im supposed to guess that it means some1 is mia. Always some1 to step in the bush every1 is pingning cause 4+ champs are in it.

Like the idea but...
When you ping your own things, it green.
Ping enemies, it's red.
Ping others, blue.
I wanna know what button you gotta press to ping for mia.
Would you be able to hold alt and press another key or something instead of clicking the ping button near your map.