I don't know about any resources for accessible colour picking, but if you're looking for a colour picker to work around badly designed charts, there's Pick[1], which is easy to work with. It also displays you the closest colour name, so you don't need to manually parse hex codes to see the difference.

I'm not aware of any colour disabilities that I have but I found it difficult to parse the colours as well, specifically in the second pie chart (areas). The colours in the chart only work to distinguish one slice from its neighbours, it's near impossible to map them to the categories listed in the legend. Perhaps the author is working on a super-colour-accurate computer screen where this problem isn't as noticeable, but on my older screens these colour profiles are near useless.

If you're in Firefox, you can find a colour picker in the dev tools (top left of the "inspect element" tab). That mostly focuses on devs though, so all you get is HTML colour hex.

[1]: https://github.com/stuartlangridge/ColourPicker