Change text colour/hover colour in menu bar

Hi all,

I have just installed the Quark theme, and I am trying to change the blue (#2997AB)active/hover colour to white (#FFF) and also the text color (#333) to orange (#F99D1E) in the main menu.

I have managed to change the link colour for a custom menu in the sidebar, but can’t seem to find a way to change the main menu.

See site at https://217.199.187.65/conti-tyres.co.uk/mtb/

Any help would be much appreciated, thank you!

Rich