Why is my display starting in Pink tint after coming back from sleep?

Sadly, this is in fact due to the SSD you put in! Using an M.2 SSD with an adapter you can encounter issues like this.

The issue is the M.2 SSD’s don’t handle the special signal lines Apple has in their custom SSD’s to hold the state of the drive fully. So your display will go pink when recovering from sleep mode! This is the way your system works leverages virtual RAM which is storage space on the drive to extend the RAM foot print.

You won't damage your logic board, but the drive/adapter combo won't last very long. I would look at getting a OWC or Transcend SSD which is designed to work from the get go in your system Vs force fitting an M.2 SSD into your system.

I had wished Apple would have embraced the M.2 interface with their SSD's Vs going there own way. Or, at least publish the interface (and the updated ones as well) as they never offered the option to upgrade the drive.

Clone system makers encountered a similar problem when the original IBM PC came out and was a success. The PC's BIOS was copywrited work so competitors couldn't copy the BIOS firmware. It took many attempts until they got it right using one group of engineers to define what the BIOS did (from a Black Box approach), then passing to a different independent group of engineers (White Room) to create from the ground up independently. Then having a a third group of engineers to test it and then pass to the first group what failed. All of this monitored by a bunch of lawyers so IBM couldn't argue it was their code.

This is a very costly endeavor! Many companies failed with customers holding the bag with a defective system. Only two PC companies really succeeded! Compaq (now part of HP) and Dell.

Thats the same issue here as these adapter makers just took the easy route, just translating the PCIe lines and not deal with the other lines Apple uses.