Current page text colour and backgroud sub menu in main menu

Hi,

I solved my other problem with the colours but this problem is to hard to fix for me.
I would like to see the colours of the main menu to be changed when I opened a submenu.

Main menu ——> Submenu A
——> Submenu B
——> Submenu C

So for example, I opened Submenu C I would like to see a colour change in the main menu when I’m on that page.
The current page background and current page text doesn’t cover the sub menus and only works for the main menu?

Hope I get an answer this time.

Thanks for your help