I also was quite confused, but when I enabled True Tone on the Macbook Air it got even more yellowish; so I can assure it was turned off and I even took a second Macbook Air (it’s cable allowed for a side by side comparison with the MacBook Pro) and it looked the same to me.
When I first looked at the Macbook Air alone I thought it was fine, but when I compared it to the Macbook Pro I was kinda shocked?!
These side-by-side images are very helpful and interesting, also the actual resolutions (not of the hardware but in MacOS)! It shows that a lot of those shiny influencer and YouTube videos sometimes are just an extension of the usual sales pitches while forgetting what really is of interest in everyday use.
I still think that the MacBook Air 15 is a wonderful laptop (and probably my choice if I was in the market right now), but it is nice to get more perspectives and to see actual display differences.