"MacBook Air M1 screen purple: I have this problem many time, when I connect external display by use with hdmi link and after I'm open my MacBook again, It's screen will freeze and show purple color after that it's will restart MacBook. How to fix this problem."
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Purple Mac Screen After Plugging in a Monitor:
A. Confim Compatibly:
Find the model number on the back of the monitor, and then find the User Manual on the Manufacturer's web site. See if it is compatible with Macs.
B. 4K or 5K, Perhaps?:
It may be a frequency error, or high definition rate. So, you man need to use a particular type of cable for this.