Change hover link color

New to WP and Sento so I am a little confused.
When you hover the mouse over a link it changes color to an orange color. Additionally when you are on a page, that page name is orange. This is the default behavior and I can not seem to find a place to change it.

I went looking through the CSS code and there are tons of “hover” codes so I dare not change one. Besides, I read somewhere that you should pout it in the custom CSS block but I don’t know what to put in there.

Any help appreciated!