Custom link colour

Hello

I am having an issue with my link font colour.

I had it set to white which works for the majority of the site. However on the archive shop page the drop down menu becomes blank as they are links and the menu is white.
If I change the colour to a dark colour, they I have issues on the product role overs. The role overs are black so you can’t read the dark text. Can I change this? How can I change the rollover button background colour for the products?
Or how can I change the drop down menu font colour for the shop archive page?