Dropdown Text Color

I need to change the text color on a drop down to Black. The web site is:
http://discountsportinggoodsonline.com/

When I hover over “Categories” in the main menu at the top I get a Grey dropdown with white text, near impossible to see.

I am using “Valiani v1.0” theme.

I know nothing about coding, hope there is some sort of “selection process” to change the text color.