To chime in:
1) A yellow screen isn't necessarily an inferior screen. That's just the screen having a different native whitepoint. These variations are normal especially where there is more than 1 panel manufacturer, and with the screens uncalibrated out of box. Most folks are visually accustomed to blue screens but that is definitely an inaccurate whitepoint for media work. A yellow screen is just simply.. yellow. Blue screens are blue. Calling a yellow screen defective is akin to saying a Granny Smith apple is rotten, vs a Gala apple. There's no basis for comparison.
The key test is whether different screens can be visually matched with calibration. X-rite used to have an app allowing calibrations (within the app), but unfortunately that is discontinued.
https://www.xrite.com/categories/calibration-profiling/colortrue
2) The real test of a defective screen should be on the following:
- Panel uniformity/banding at various greyscale settings (5%, 10%, etc)
- Differences in native gamut (are certain RGB subpixels weaker than the others?
https://en.wikipedia.org/wiki/PenTile_matrix_family)
- Panel durability (how subpixels age across time, if there's nasty pink colour casts like the older generation LCD iPhones)
And more... but definitely not because it's a yellow screen. You can try to play the panel lottery by trying to get a blue panel iPhone, but yellow panel iPhones are not defective.