How to change a button color to distinguish what page you are on?

I have a blog page with different categories and buttons that lead to the different categorical pages; these categories being "all", "current", and "non-current". I am trying to find a way to change the button colors once you're on a certain page so that users can identify what page they are on more easily. My buttons are light blue at the moment but, for example, if I am on the "current" page I want the current button to be a different color or have an outline to distinguish that you are on the current page.

Hi. Can you share link to blog page? We can check easier