Phone number header not shown on mobile device

Hi there,

I saw this question was asked before but not solved.

On a laptop you can see the phone number in the header above the menu but on the iphone it’s not shown.
BUT if you click next to the phone symbol the number is there and then shown in green.

How can the number be shown in white like the email for example?

Thanks for your help!

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