I always thought the black and red for the bombers came out of the war-time images of bombing raids at night and the red represented the fires caused by the exploding bombs. Could be wrong though. Around our place the crows are black and there is black on the Crows jumper isn't there?
I reckon you might be a bit off there, they had a black jumper with a red sash back in 1897.
Mind you, ours was like this in 1908:
We got the sash in 1914, see: https://www.footyjumpers.com/
DS