What ever happened to applying the principle of contrast in user interface (UI) design? The Nougat update for the S7 results in thin, blue wire-frame icons against a white background for the quick settings screen. In low light conditions, especially with the new blue light filter activated, it is hard to see the flashlight icon when one needs it, like at night when one is trying to use the LED flashlight (third icon from the left on the screen shot below): try this on in the dark on your S7, it may not be so evident from the screen shot below, if you are reading this from a computer screen.
The issue is not quite as bad in the full settings screen when you have orange wire-frame icons against white (below). The grey wire-frame icons against a white-background in quick-settings is just really bad design.
As already noted I highly recommend looking at other themes. The Samsung theme store has lots of options. I've been using a theme since back when I got the S7 running Marshmallow. While I do greatly like the UI improvements of Nougat (Android 7) over Marshmallow, there is definitely an issue of lack of adequate contrast in the default UI.