On the Samsung Galaxy S8, there is no home button for the first time. Instead, there is now a navigation bar on the lower edge of the display, in which the home button is integrated as a soft-key button.
For the navigation bar you can customize the color according to your wishes. How to do this and where to find the setting, you will find here:
Navigation bar - Customize colors
1. Starting from the start screen, first open the app menu and then the settings of the Android system
2. Next select: Display --> Navigation bar
3. You can now see different colors, which are pre-selectable. Here there are:
There is also the possibility to occupy the navigation bar with a desired color. Thus, a color from a huge color palette can be selected via "individual". It is nice that the Samsung Galaxy S8 offers the possibility here to adjust the navigation bar color individually.