Mini map colors

I’m cat D and in today’s race, I saw a few purple dots on the mini map and assumed they were E cat riders.

I’m watching Gerben on YouTube and he is cat A in a mass start 0-1000 race and the only dots I see coming off the back are purple.

Does purple just mean rider of lower cat or different cat?

So it looked like everyone was a purple dot.
How does that work?
Are racers in mass start races having adjustments to the ZRS?
Why can’t they keep the 6 colors and add more if and when we get more cats?
A+ black
A red
B green
C blue
D yellow
E purple

They could easily use white, brown, pink, .

I hadn’t noticed that the colors had changed.
I hope its not like this long but they said they were changing the map so maybe it is short term.