[DerickClark]

The code is wrong.it's not going to work with _ in the command.

Code:

COMMAND:colorgreen(playerid, params[])
{
    SetPlayerColor(playerid, 0x33AA33AA);
    SendClientMessage(playerid, 0x33AA33AA, "Your Name Has Changed To Green");
    return 1;
}

Do /colorgreen (ingame)