I primarily played around with it using nocoffee extension in Firefox (soon coming to firefox devtools accessibility panel!!) and simulated different types of colour blindness. It works reasonably well when there are only 2 types of data plotted on the same graph, however after adding more things get a little worse (colours become less distinguishable). I don't believe it is any worse than it used to be before the changes (if i'm looking at the right thing).
A really awesome improvement to this would be distinction of points from different sets of data not just by colour but also by shape! Right now every point is a hollow circle. It would be really cool if for each new data set the point representation would change to, as an example, square, triangle, filled alternatives to the same shapes. Thoughts?