The sun should be a little yellow due to some of its bluer frequencies being scattered away from the beam going from the sun to your eyes by the molecules in the atmosphere (thus resulting in a blue sky). This is called Rayleigh scattering, and it happens to a degree proportional to the fourth power of the light’s frequency (blueish hues having higher frequencies than all other colors except indigo and violet which we’re less sensitive to, and greenish hues also being up there in wavelength thus making the sky more cerulean than true blue).
But yeah, the sun really does largely appear white, so I’m not sure why it’s traditionally depicted as yellow in drawings and such. Maybe it’s due to its association with yang energy, or due to yellow being perceived as a very bright color (and also the closest pure hue to white), or due to its association with fire, given that we tend to instinctively think of the sun as being a big fireball due to its immense brightness and heat, and considering the fact that you couldn’t very well color the sun and its rays white on the typical drawing background of white paper. Oh yeah, and the sun does actually appear yellow when it’s close to the horizon (because then there’s more atmosphere in the line of sight between the sun and you), which is when it’s the easiest to look at.
But I know a guy who believes that the world is made up of a pastiche of slightly different collectively constructed realities, and that the timeline is shifting all the time via what essentially amounts to the Mandela effect, and that the sun is depicted as yellow because it actually used to appear yellow. (I should note that if this is true, it could also be part of the reason we tend to instinctively see the sun as a big fireball in the first place.) I suppose, since this is the Mandela effect, this change wouldn’t actually be noticeable by looking through, say, old photographs or past spectographic measurements; it’s only noticeable as an anomaly in our cultural memory.
As evidence of the pastiche of different realities, he says he once came across a forum full of people posting about how they experienced subtle changes in reality when traveling from continent to continent. I myself have read of someone noticing the segments of his fingers being inexplicably longer while on an international flight, and also of someone noticing that anatomical depictions of the human heart looked more like the shape of a bota bag or something in some country overseas.
Oh yeah, and personally, I noticed when I traveled to the Philippines (opposite side of the world from here) that the sun seemed inexplicably less harsh and glaring than it is here. It was just less bright; I had no problem looking directly at it, and my eyes have always been extra sensitive to bright sunlight. When I was a kid I would curl my fingers in front of my eyes like binoculars and squint just to be able to see while I was outside. And I tried looking at the recent solar eclipse the other day, and even coming close to looking directly at the sun was unbearable, so I immediately gave up. I can’t think of any astronomical explanation for the sun appearing different in the Philippines. It wasn’t at a low angle in the sky, and the air didn’t seem polluted, and if it were then the sun should have appeared discolored, but it appeared white.
Though differences in reality across distances probably aren’t as relevant to why we think of the sun as being yellow as shifts in reality over time are, but this guy I know also claims that he once met a very impressive group of people at a festival or something who told him they could send him to any parallel reality, and then performed some ritual on him, and ever since then many things about his reality have been very different. He also says he requested that they send him to a reality that has an immortal jellyfish species for some reason, and this one has it (Turritopsis dohrnii), while his old one didn’t.
This guy is a little crazy, though. If I remember correctly, he believes in flat Earth. But he can also be very insightful in some ways and tends to see things from a culture-independent, bird’s-eye-view perspective.
And also, I’ve personally read many, many stories right here on Quora, as well as from other places, of people experiencing their reality changing, or things otherwise transpiring, in ways that were deeply confounding and should be impossible. For example, the story where a father and son pull into a gas station in the middle of nowhere, staffed by two very strange sisters, where the father buys a pack of donut holes, only to discover a few minutes later that the gas station is nowhere to be found (I forget how they found this out), and then the father goes to take a bite of one of the donut holes as he’s driving away and it’s hard as a rock. Again, that’s just one of many such profoundly eerie accounts I’ve read.
And my own mother and sister have had their own experience with the timeline shifting, which I wrote about here: Richard A. Nichols III's answer to Have you personally experienced a Mandela Effect change? Will you share your experience with us?. Here’s the relevant part of the post:
“There was a house next to a church nearby that my mom noticed was gone one day, leaving just the empty lot, so she just figured they’d demolished it for whatever reason. Then another day she noticed it was there again, then a few days later it was gone again. I think she probably just assumed her memory was faulty, but it seemed odd enough to her that she happened to mention it to my sister sometime later, and here’s the weird part: my sister replied, “you too!?” She had noticed the same thing: that the house was there, then it was gone, then it was there, then it was gone again!
Here’s a link to the property on Google Street View: Google Maps”
There’s also a story of my own personal meager experience with the Mandela effect in that Quora post. And no, my mom and sister don’t entertain outlandish possible views on the nature of reality like I do. ;P
Edit: I was confusing two different people above; I’ve known two people who claimed to have an experience with shifting timelines.