To reproduce: When on the staff interface home page, try tabbing through the page elements. Notice that is hard to see which page element is selected. Suggested changes: Changes could include a bolder hover text, shading the whole box/button when selected or bolder shading/colour change if strengthening the outline highlight of an element. I only tested the Koha staff home page, but this could be a bit of a project working through all of Koha looking to improve visibility/contrast.
I was thinking the same thing while working on Bug 26808
Yes I saw you have been working on a bunch :) This is a topic where once you start looking, there is a lot to do, eh. I wonder if this kind of thing could be added to the coding standards, so if you're working on a particular page, people could also do x to all the buttons, y to all the hover/highlighted text changes etc. I am not sure where that discussion should live, or if that's a practical idea. But maybe we change this page as an example.