If you notice on your Samsung Galaxy S6 that the display flickers pink or flashes, then you have most likely accidentally activated the following feature: Show screen updates
This option is located in the developer options and is intended to indicate when the image areas are updated on the display. Because this option is usually only useful if you are a programmer, you want to disable certainly this option now.
We show you how to do that on the Samsung Galaxy S6.
Open Menu --> Settings --> Developer Options
Scrolls in this submenu a little way down to "Show screen updates". Remove here the hook in the checkbox. Finished!