I find the black Android Oreo UI so cheap looking. They make it look slightly better in screenshots. Is this possible to achieve or are they just cheating?

I can't stand the dynamic background crap. In fact the whole Oreo UI is kinda crap.

Buy a Nexus Player. As you scroll around the color of the background changes changes to somewhat match the icon.

I got it for you! Enjoy!

I don't know how you get it but I know that I want it!

Have you tried hovering on the YouTube app as they do in the screenshot?

Well this thread is already 4 years old but as I was just looking for the same background and I couldn't find it, I created it myself and thought I will share it.

I created one version, using the four corner colors, and made one gradient. As I ended up with some banding, I added some noise to make it look smooth.

For the second version I just took two colors for the gradient, bottom left and top right, but I had to add some noise too.

I hope in the future I will be able to create a gradient with 32 bit, so I can spare the extra noise.

Original (4 colors) | second version (2 colors)
(btw: the Google preview looks more messed up than it is)