After hearing how Nintendo started using different (worse) screens in more recent Switch consoles I compared a load of units in person and found 3 different types, one of which is no longer being used. The launch era screens are super bright and colourful, they seem to have been using them to some extent up to the launch of Odyssey. From mid-2017 onwards though they've been using two other types, one of which is nowhere near as bright but still good (as long as you don't put it side by side with a launch one) and a second one which is just as dull and has an AWFUL yellow tint that is super noticeable. If you buy a Switch now it's pot luck if you get the decent screen or the atrocious yellow one, although the latter seems to be rarer.
Thankfully I managed to find a brand new Odyssey bundle with the launch screen and promptly snapped it up, I was holding on for a nicer special edition unit or price drop, but the difference is so noticeable that I just had to bite the bullet.