I don’t understand. If you can’t differentiate the colors, you can’t see the boundaries between segments. I think it would have been good to include tables, as well.
EDIT: I see what you’re saying now. You can just read the legend, which lists things in order. But that just gives the ordering, not the sizes of the categories.
Different colors can be differentiated, it's the three yellow colors that are similar, but don't need to be differentiated, they aren't consecutive.
There are different kinds of colourblindness. Deuteranopes are likely to confuse greens with yellows, which are consecutive here.