Dual/changing color on mobile header!

Hi all,
what i need is this:
to create a transparency effect on mobile…ive set menu color the same as the top pixel of the header photo…so it looks seamless.
But what i need…is that top changes color…just like desktop version.
So on open…its transparent…and on scroll…it turns white.

Basically…what i need is mobile version acts the same as the desktop version…(with transparent header option activated)

So: if you select transparent header…and menu bg color #fff…it wil do exactly that on desktop…but on mobile its not transparent but white…so the question is: can this be fixed!?