In most devices, pinky colors and black spots on the display usually occurs when there's a loose cable or LCD wiring faults on tablets. Same thing can also occur on smartphones including the S6.
Unfortunately, hardware problems like this can only be resolved by a technician. This means you need to take your phone to a repair shop for hardware checkup and repair. But if you are highly skilled on such tech-stuff and possess enough guts to do the repair by yourself, then you can try to open the phone, check the connections, and secure those that you found loose. Just remember though that doing this will void your phone's warranty.
On the other hand, screen flickering problem can also happen due to a software glitch like a buggy application. There are also some cases when the display flickers after updating the device software. Apparently, it's the update that's triggering the problem.
If the problem happens after installing a new app, then try to temporarily disable the app and see if it'll fix it. Once you've proven that the newly installed app is causing you this trouble, then you can decide to either remove the app or contact the app developer to escalate the problem and have them fixed it. You can also try running the device in safe mode to see if other third-party apps are triggering your phone to act this way.
Here's how to enter Safe Mode in Galaxy S6:
- Power off the phone.
- Turn the phone back on while pressing and holding the Volume Down button.
- Keep holding the Volume Down button until you see the Home screen displays.
To get out of Safe mode, just power off the phone as you normally do by pressing and holding the Power button, and then select Power Off from the given options.
In case the screen flickers after performing an update, try to reboot the device (soft reset). If a soft reset won't do any good, then your last resort would be a master reset, which will restore device to factory defaults. Please note though that all your personal information and customized contents stored in your device will be erased in the process. So you might as well consider backing them up beforehand.
If a master reset is not your choice and the problem happens after updating your Galaxy S6 firmware, then you may contact Samsung Support or your carrier to escalate the issue and ask for recommendations.
For more problem solutions and troubleshooting guides, please visit our troubleshooting page for Galaxy S6 device.