In the "high contrast mode" on Mac OS (chrome browser) the instructions do not pass WCAG contrast tests:
Drop files here to upload

Found another one! I think? The "errors" in the console:

thanks for reporting! i need to figure out what these colors should be.
Moreover, in Dark mode, there doesn't seem to be anything written in the window (on Manjaro Linux, with Firefox):

After inspecting the element, it turns out the text is simply white (#fff). It should probably be #333, like in the light mode theme.
And another one : (the error message "Please enter a name")

(On ArchLinux with Chrome Version 70.0.3538.35)
thanks for reporting more issues!
and also on login page

Hello @catarak , I'd like to help fix this issue. Is anyone working on this already? Also, what is the minimum accessibility level you'd like to support, AA or AAA?
I plan to fix this by using darker shades of the same colors that were being used, so as to not alter the UI much, but if required, I'll change accordingly. I'll also post screenshots of my changes in my PR.
i don't think you'll have to change too many of the colors, and i would try to change as few as possible. the contrast theme was designed to pass the appropriate guideline, however, some color values haven't been set in the right way, and some newer colors got added that don't pass (e.g. in the console).
Is this fixed? I can't reproduce it because I don't have a Mac.
some of the contrast issues have been fixed, but others have not been.
It would be nice to know which are addressed and which aren't. I was going through issues and tried to take the old ones. This one is almost a year old. I'd like to try fixing it. But there was a conversation about design decisions. Not sure if I can actually pick this one.
the uploader one has been fixed, but the rest have not. i think it would make sense to break out some of these tasks into smaller issues, so feel free to open some new issues! another very useful task would be doing an assessment of the color contrast across the application and opening issues for that.
That's a very good idea. I'll get started with that soon. 馃檪
Fixed by #1406.