MBPr screen flicker and screen dimming

I have a mid 2014 MBPr that's only a couple months out of warranty. About a month ago my screen started to flash bright pink boxes whenever I wasn't typing or using my trackpad. I immediately backed up what I was working on and reset the PRAM. I saw the same flickering after restarting so I tried restarting another time. This seemed to solve the issue temporarily.

A couple weeks later same thing happens. I made sure to get video of it so I could show it to an Apple genius. I brought it in the next day and waited a couple hours for an open spot and was just dragged through the standard procedures: Reset PRAM and run diagnostics. After everything passed I was told it was probably a software issue, basically it was my fault -- I'm a web developer and have programs installed throughout my computer, Apple Genius noticed that and said it was probably something I've installed. I haven't installed anything in the last 4 months, and I find it hard to believe one of the well known and trusted programs I'm running is the culprit of my flickering screen.

I have an external monitor and everything is fine when I'm using it, so it's something with the devices screen. Here's a list of a few things I've noticed with this issue:

• Flickering screen when not constantly typing or using trackpad
• Slight dimming to an almost yellow-ish screen then returning back to it's normal colors
• 1 second black screen flicker every few minutes
• When rapid flickering happens, it seems to always be pink and yellow lines along with other geometric shapes
• Apple logo also flickers when the screen is spazzing out
• Works perfectly fine when external monitor is used as the only display source

Here's a video of the pink-ish geometric shapes flickering on my screen: https://www.youtube.com/watch?v=jzMnWbh6eLs

Has anyone else ran into an issue like this?