Created attachment 13407 [details]
Only when all things have been painted blue can a perfect world society be attained
On Mac, the "default" button in a dialog (the one which will activate if you press the "return" key) is highlighted in a special way. As of El Capitan this is done by highlighting the default button blue, but this has been present in some form since at least System 6 and it is an extremely expected part of the mac user experience. Xamarin has dialogs which have a default button you can activate by pressing "return" but it is not highlighted.
Reproduction steps: Running Xamarin Studio Mac [XS 5.10 Build 811, OS X 10.11 15A284] I click File->New->Solution. A dialog pops up. There are multiple buttons, but none have the "default" styling. I hit "return". "Next" is automatically selected, so it apparently is the default button.
Expected behavior: "Next" should be blue.
Observed behavior: "Next" looks the same as "Cancel". Screenshot attached.
You can see the correct behavior in basically any system dialog on the mac, such as Edit->Start Dictation... in Finder.
If this is a GTK problem rather than a Xamarin Studio problem, it should be fixed in GTK also.
To be fixed in GTK.
This should work correctly in XS 6.X.