Yup, i know, its just not possible atm. But thank you anyway :)

Where can i change easily accent colors in Gnome without using extensions?

Thank you, bookmarked. Never heard of this yet. :)

I totally agree - Apple invested alot of cash and time into this, just take it and make it better here and there. Just a few steps left :)

They should simply find the courage to implement Apples Human Interface Guidelines. It wont hurt and they are almost there anyway.