Menu colors in Twenty Seventeen

Hey guys,

I use the Twenty Seventeen Light color theme for our website, but when viewed on a mobile phone, the menu items is only visible on roll over as the background and text is white.

I have also noted that the color slider/picker underneath Customizing – Colors has disappeared, and so also everywhere else I can customize the color. (I have installed the Twenty Seventeen Advanced Plugin)

I am sure at one stage I could change the menu color as well as the roll over color.

I am coding disabled so please be gentle. I have inherited the site from our brain IT coder dude, but he is too busy with other stuff to assist.

Thank you

Hein

The page I need help with: [log in to see the link]