This makes the tabs slightly larger, increases the text size slightly, and adjusts the colors a bit to improve overall contrast. It also makes inactive tabs draw with a full tab shape, improving the readability at a glance, particularly when tabs are very small.
The users most affected will be those on smaller displays, where previously tabs were very difficult to read.
Reviewers: @billrey, @campbellbarton
Differential Revision: https://developer.blender.org/D170
b3101aba6a