External display color changes when MacBook lid is closed I have no idea how, as the color profile remains the same, but whenever I close the lid on my MacBook, the external monitor changes to a blue tint. 

I've tried changing the monitor's settings, as well as ensuring the right color profile is on.
If you update to macOS 10.15.4 it may now detect that you have a HDR screen, and makes your external screen colors look weird. 

To fix this:


Go to Display settings 
Uncheck "High Dynamic Range" for your external display 
Everything should be back to normal.