Huawei has a theming engine built into EMUI, its custom Android skin, and a number of themes come pre-installed. But the community’s made themes of its own, and one of the most visually impressive is from XDA Senior Member mr.mrcn. His dark mode for all EMUI 5/5.1/8 devices (like the Mate 10) inverts the colors of almost every menu, home screen, and application shortcut.
Applying it couldn’t be easier. All you need to do is download the EMUI Themes Factory app from the Play Store, tap Install Theme, and then open the Theme Manager within EMUI so that you can switch to it. After you reboot your phone, you’ll see it applied.
Check out the forum post for more detailed instructions.