The mortar smoke-bomb (smoke colour to taste) on target worked fine in Burma in '43/'44. Don't think there was ever a blue-on-blue with Vultee Vengeance operations.
Very occasionally a squaddie would get up too close to the action in his eagerness to start the mopping-up when we'd finished, and there was a "wild bomb", but that was just hard luck.
RIP all.
D.