Light Pressure on Logic board causes screen/Mac malfunction

There are no software fixes for hardware problems.

Your description fits a "cold solder" or "fractured solder" connection failure on the logic board, possibly related to the GPU (screen color change is a hint). If not the actual GPU (you can rule this in or out, by connecting to an external monitor - if you see the same thing as the on-board display it's the GPU) It could be connector or controller on the logic board, if not the fault must be part of the internal display chain.

Another reason to suspect the GPU is the freezing under high graphics activity.

If still under warranty see Apple. If it's not under warranty, and you believe it is the GPU, you could either just replace the entire logic board (an advanced DIY project - you basically completely disassemble then reassemble the laptop) OR you could remove the logic board and try having it repaired by one of the services on e-bay.

Soldering logic boards requires special tools and lots & lots of practice, so as not to destroy the MLB with too much heat. If you can determine you have a bad logic board connector or component a local electronics/computer repair store may be able to fix a lose connector or bad component.

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