Yes, my question was how many pass it after failing the Ishihara plate test.
Why else would you take it? Most if not all ATPLs will not have taken it. I haven't heard of anyone passing it after failing the colour blindness test at their medical.
One further site of interest is
Colour Vision Defective Pilots Association (CVDPA)
This explains what happened in Australia.
Their principal is based on agreeing that they are colour blind but arguing that it doesn't make any difference to your safety as a pilot.
For those that are not colour blind, it is a complex subject and non of us are really colour blind. We see colour, but slightly differently to the rest of the population.