We can't really see the Sun midday in a clear sky, it's just too bright, we see it at sunrise and sunset and it appears yellowish of reddish because of atmospheric scattering. Hence the yellow sun in artwork. Seeing it as white when there are clouds and appearing white probably just has not occurred to the lay person.
Yes, a setting yellow Sun is far more, well, colorful than that painful bright object overhead. Certainly more interesting for artists.
Our atmosphere reduces an overhead Sun (AM1 or one atmosphere) by very roughly 10,000 times when it is setting. This amount of reduction is needed to put the intensity to a more comfortable level. If the atmosphere is clean, even a setting Sun can be a bit painful, and it isn't all that yellow if that is the case. Here in Texas, we get enough dust, etc., to often see very yellow solar discs when setting. This would be the safe time to see and enjoy the Sun, and look for sun spots, but this should be done through glass of some kind -- the IR intensity is almost as strong as overhead. This can damage the eye if unprotected. So be warned!
Also, remember that our color detectors, the rods, come in three flavors, red, green, and blue.
Yes, we have those "flavors"

, but they are the cones; the rods are very sensitive to all the visual photons but they only give us a gray rendering. We usually ignore this fact, but if you are driving somewhere in the evening, you can enjoy noticing how the colors all around you fade as the it gets darker, when the rods are hard at work. They happen to be most sensitive to green, hence many emergency vehicles are painted green to allow greater visibility in the darker hours.
Helio's white sun avatar appears white because all three emitters in your monitor transmit all three colors equally, your eyes detect all three colors equally and your brain interprets this as white.
I'm curious if the output from the screen is in photons/sec, or energy flux?
The aforementioned avatar was captured either on en electronic detector capturing the image detected by CCD pixels, or by film. In either case, because the image brightness is saturated, all the detectors or film chemistry will capture it as white.
It was a Canon Rebel, IIRC. Cameras try to reproduce color accurately, which requires software. The software, as I understand, benefits greatly when there is a reasonably bright white object in the image. This is the preferred reference color for processing more accurately.
[I'm using "saturation" as the maximum useable flux density the cones can operate within photopic vision. ]
But, the projected Sun in the observing room at Kitt Peak has expanded the size of the disk enough to prevent saturation. It is quite comfortable looking at it. The color pieces in my avatar demonstrate that the light levels were within norms.
But, you raised yet another important argument for a white Sun. When the cones are saturated, then white is the result. So, even if an object clearly is seen as blue, if its intensity, along with the weaker colors, are bumped in flux high enough, when saturation occurs, then it will become blue-white, then with more intensity, white. This is addressed in what is known as "color constancy". Color constancy shows how our brains (retinex per Dr. Lamb) process color by converting the irradiance from the brightest source and converting this to be the "white" source to process the other colors.
I recall an article in Sky and Telescope many years ago that white objects appear white because although the Sun emits a bit more yellow than the other wavelengths,...
I bet they offered no evidence, but consensus, that yellow is the strongest color emitted. The data is very clear that blue is the strongest solar emission energy, not yellow. The graphs above alone demonstrate the error of such a claim. [Oddly, however, if you closely at my photon flux graph you will see that yellow is the peak point, but this isn't a peak, but a little pimple

. The intensity of the other colors will wash out any yellow result, plus the band size of yellow is the smallest, hence total emission from the yellow band is lower than any other.]
I got serious about the Sun's color for two reasons: (1) When enjoying the fun in being in an astronomy forum, the forum's founding astronomer, Phil Plait (
Bad Astronomy) stated he was unsure of the Sun's true color. (2) Then I soon read an article in a science magazine written by an astronomer on the East Coast that claimed the Sun was a bit green! The article did a great job in presenting how the eye operates, but a green Sun? Crazy that they were this far off. So, I saw no reason why an amateur astronomer couldn't step in and research this topic more seriously. I tried many things, but my avatar, as it turned out, was all that is needed, as stated above. [Find "QED" and the sentences before it.]
... the light reflected from a white object is pretty much saturated, hence the white color.
Saturation of your color cones is uncommon and often comes with pain. If you look at a white object and you have no trouble seeing colorful objects around it, then saturation has not occurred. [This is another reason for those color pieces in the avatar.]
If we were on a planet orbiting a red or blue star, the brightness would cause white objects to appear white because the light again is saturated. An image of the star from up close would likely appear very much as Helio's avatar. I imagine from a far distance, the Sun would appear a bit yellowish not unlike how we perceive similar stars from here.
Why would a star with weak yellow emissions appear yellow? If they have the same color constancy effects, even somewhat greater yellow emissions would favor a white result, ignoring atmospheric effects, of course. It should be no surprise that most stars appear white when we adjust for atmospheric effects. Often we see stars like Capella with a yellow tint, but this is due to atmospheric effects, IMO. From space, I wonder what color Capella would have?