Hello,
First of all - thank you so much for the amazing additions to the RStudio IDE lately - the D3 support + running background jobs + amazing python support !
I've been struggling a bit with the Spyder IDE for python (which is nice editor...) and realised that we've been quite "spoiled" having RStudio 
I got the 30 Aug daily build RStudio 1.2.937 build 940 (d1f960eb)
and I noticed that using ? in the python repl to search for help docs works when using a light theme but it breaks when switching to a dark theme - but only for some items...
The text get displayed in the help pane but it becomes unvisible due to dark font on dark background.
Example with bright bkg:
Example with dark bkg:
However - it works fine when searching for ?dict for example.
I thought to report it here. Thanks again for all the great work.