Risalto Dark is a Substratum Theme compatible with all ROMs that support Substratum.
It also supports Samsung devices (Nougat and Oreo).
Themed elements are many; the main color is dark grey (in all his shades) and the accent of the apps is like the stock color is.
If you don't know what Substratum and root are, maybe this application is not for you.
You can choose from different colors accent like blue, teal, grey, red and many others...
If you have any kind of problems enter in my community https://plus.google.com/u/0/communities/116482913216113266578 and make a post or send a mail to: firstname.lastname@example.org
If you like Risalto Dark don't forget to leave a review.