Hamburger Options Disappearing

Dear Wes,
Thanks for the awesome themes. Looking forward to some more.

I’ve used the SquareOne theme and I’ve noticed if you have a look at the menu options on my site http://www.mrpkalu.com on a mobile, the text is white on the home page. It becomes black on other pages. The drop down menu options text is then white and so disappear when the header section is white.
How do I change the text colour to remain black when viewed on a mobile?

Thanks for your help as always.