How to change the color of header links

Hi

Does anyone know how to edit the color of the main header links in the Minamaze theme?
I have tried editing the color using CSS but when I save the CSS edit and refresh the homepage the header links are still the same color.
This is the CSS edit I thought would work but it hasn’t:

#header .header-links > ul > li a {
color: #ffffff;
}

Any advice or help would be greatly appreciated.

Thanks