Since I prefer white texts on dark background, I customize all the color settings.
After I change the Binder Background Color, it goes back to gray every time when I switch to other applications (as well as when Scrivener Preferences is open). Also, the title texts in Outliner mode remains black and become difficult to read after I change the Outliner Background.

These are not bugs.

The outliner text is always black (it only turns white if the row colour is too dark). This is standard for such controls on OS X.

Source lists in OS X always turn grey when you switch to other applications. But you can prevent Scrivener’s binder from acting like a source list by deselecting “Binder uses source list style” in the Appearance preferences.