Chosen Solution
This is an early 2009 MacBook Unibody. When using it recently, the display suddenly turned pink. All images and text are visible just with a pink/magenta hue that is uniform across the display. It is almost like the color balance settings were changed but I have confirmed they are normal. I tried resetting the PRAM and SMC with no change. I reseated the connector on the CPU side with no change. Connecting an external monitor (e.g. my TV) works perfectly so it seems to be isolated to the MacBook display. The computer otherwise functions normally. Talk on the internet suggests it may be a bad cable between the display and computer but wanted to gather suggestions here first. Thank you!
Try connecting to an external monitor to see if it shows up there. If it does your GPU is having problems, if not your LCD display and/or the display cable is bad.
It sounds like a problem with the display cable. You’re going to need a new display cable. Apple only sells the display as an assembly. Since Apple does not sell this as a individual part, you will have to either buy a used one that’s tested to work or buy a damaged display assembly from eBay. If you have any local small businesses who do 3rd party Mac repair, they may have a damaged assembly with a good cable they are willing to give you for a few bucks, or even for free if they want it gone. You can find a cable and guide here, along with the link to the full display assembly: 13" Unibody LVDS Display Cable MacBook Unibody Model A1278 LVDS Display Cable Replacement MacBook Unibody (Model No. A1278) Display Assembly
