In desperation once after clouds came in after I had L, R and G images I tried to make a synthetic blue from L, R and G
(technically L is R+G+B so can do a bit of creative PixelMath and, with some cost from excessive noise, reconstruct a set of blue images).
I never achieved that misguided goal as the image never quite could be made to look right.
Sensibly, next clear sky chance I got I added some B images