Mac randomly crashes, screen turns green and white, and it works fine upon restart. What causes this and how can I fix it?

Are these 'crashes' kernel panics? If so log and post one per these instructions:

https://support.apple.com/en-us/HT201753

Ciao.

The image suggests an issue with the graphics board.

The issue may happen more when your machine is generating additional heat, as when you're watching or processing video, or gaming. I can't say for certain, of course, but certain things will reduce the chance of the problem recurring:

1. Keep your machine as cool as possible. When there's additional heat, turn up the fan, or use an app like HD Fan Control to reduce the heat. Use your computer the way you see fit, but be conscious of heat.

2. Back up on a regular basis. Logic board problems can lead to more serious issues down the line, so backing up is a good way of safeguarding your data.

3. Look up "Logic Board Woes" on Google for a comprehensive discussion of the issue.

Make an appointment at an Apple store genius bar for a FREE evaluation. Your MBP has a hardware problem. either GPU or display related.

Ciao.