I get that the colour is an ‘off’ choice for a wedding, but to be honest, when I got married, admittedly in the dark ages, I was thrilled that people came, and I cannot honestly say I noticed much as I was very much on a ‘wave’ of wedding joy.
I am sure everyone thought you were a beautiful bride OP, and if they noticed SIL, it would very much be with the idea that her choice may be a tad wrong, but not hugely so.