Define text-selection color specific for navbars

[deshack]

Text selection colors (for normal text and links) was defined with the content area in mind, but we should redefine that colors for the navbars.

And remember, we have 3 color schemes for navbars.

--- Want to back this issue? **[Post a bounty on it!](https://www.bountysource.com/issues/4844993-define-text-selection-color-specific-for-navbars?utm_campaign=plugin&utm_content=tracker%2F972380&utm_medium=issues&utm_source=github)** We accept bounties via [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F972380&utm_medium=issues&utm_source=github).