Coloured Gi do have a place in Judo,

as a Referee, I find deciding who did what during a
fast moving Shiai is easier when one fighter is wearing blue.

I am one of the lucky ones who can afford several Gi..........I have 15 of them,
3 Blue, 10 White, 1 Red (from the Kugatsu Judo Club Team of which I was a member for many years) and a Black one because it was given to me as a gift.

I only allow White or Off White Gi on my mats, and the only time I have ever worn a Blue Gi to training is when I could not get a White Gi dry due to weather conditions.

My students are instructed that coloured Gi are not permitted in the Dojo, and as I am usually the person who orders the Gi for a noob, I ALWAYS get them White or Off White.