These are some interesting results and I’m not sure, if the amplitude of the channel is corresponding to the importance of it.
Did you check, if the green color channel of the input images was “adjusted”?
E.g. wouldn’t the weight in the green channel be larger, if the signal from the green channel is smaller in amplitude? 
However, as a red-green color blind person, I cannot confirm the assumption of a higher sensitivity towards red and green.