Mobile Menu – Show subitems by default when opening mobile menue

Hi,

I have a menu structure using two levels.

EXAMPLE:
– Menu Item Level 1
– Menu Item Level 2
– Menu SubItem Level 2.1
– Menu SubItem Level 2.2
– Menu SubItem Level 2.3
– Menu Item Level 3

When viewing the page on a mobile device and when clicking on the menu toggle only the first level pages are displayed. Is there a way to display the second level pages in this menue by default? In this example the “Menu SubItem Level 2.1, 2.2 and 2.3” Items?

Thank you very much for your help!

PS: And does anyone know, how to change the color of the mobile menue toggle (from black to white)? Thanks!