Color of judo uniform has no effect on winning. Contrary to previous studies and widespread belief, new research on competitive judo data finds a winning bias for the athlete who is first called, regardless of the color of their uniform. Source 2l
Image from Wikimedia public domain.
Judo is one of those martial art forms that I never quite understood for practicality. Usually avoiding confrontation but this one encourages you to get up and close. I can see Judo being used as part of the techniques for self-defense but not all on its own.
Analyzing successful Judo throws. Researchers use statistical methods on video data to quantitatively determine the biomechanical techniques correlated with successful judo throws. This work may assist in developing supervised or self-guided training routines. Source 9x.
I practiced Judo for a few years when I was young, mostly because my father was a very skilled judoka before he hurt his knee (He did not took an arrow to his knee tho) and it is mostly about using the enemies' movement against them.
It's a pretty recent martial art as well (Around 100 years old) and it was created from the japanese ju-jutsu, so I think that's why it does not look so much as other martial arts that try to 'avoid confrontation'. I would not say it's mostly self-defence tho.