At 1 AU, our Sun looks
white to our eyes. There are two reasons I have found for this.
First, our eyes are "white balanced", as they say in the photo-video-chromaticity trades, to noon sunlight.
Second, in noon sunlight, your color receptors are overloaded with photons and all you can see with, effectively, is your cones, which are essentially grey scale, or b&w, if you want. I have a suspicion that most (not all) stars, if they are seen at the same apparent magnitude as the Sun, will look white, due mostly to the second reason - we just don't see color well in the dark or at extreme brightness levels when they are swamped out.
A very cool, dim star may well appear colorful to the eye if it simply cannot be seen to be as bright as the Sun, no matter how close you get to it. Due to the similarity of stellar spectra to blackbody radiation spectra, cool stars end up with more of their visible energy (in fact, the preponderance of all their wavelengths) at the red end of the spectrum. Hence, giant Betelgeuse, which is much less bright than the Sun at its distance from us on Earth, exhibits redness in its coloration. Part of the reason that it looks so bright and big is because it is huge, even at its distance, so it has a very large "radiating disk" from which its visible light emanates. Were we to travel closer and closer to Betelgeuse, my speculation is that it would change from reddish and bright to pinkish-white and extremely, uncomfortably bright, to just about white as its radiant energy intensity swamped out our color receptors (cones), and we were looking with only our rods.
At the other end of the spectrum, the extremely radiant "blue giants" end of the H-R diagram, the bulk of their light comes from arc mode delivering photons in the gamma and X-ray part of the spectrum, down through far UV, and into the blueish-violet end of "our" spectrum, the "visible" bands. Their colors, at great distance and low apparent magnitude by comparison with our nearby Sun, are bluish white, (not dark blue-violet). While these stars deliver much more total energy in the infrared, red and on up through blue end of the visible spectrum, their entire visible spectrum is, in absolute magnitude, much greater than the Sun. If you were a distance away from a blue giant star so that its apparent magnitude were the same as the Sun, and you put the Sun that same distance away, the Sun would be a dim and yellowish point of light to the naked eye, and the blue giant probably would be... white, and too bright to look directly at. To the eye.
Photographic films and CCD's have distinctly different color reactions than do our eyes. We use filters and different spectral sensitivities and all sorts of tricks, down to false color manipulations in computer-processed images to get images to "look right" to our eyes. Even photo reproductions in magazines are processed to "look right", which often means, using a limited palette and number of inks on paper or phosphors on-screen, we see only an approximation of what the real image would be like if viewed directly.
For a nice little tutorial on some of this,
link here.
This is a really seriously interesting subject. There are web sites devoted to approximating, in RGB or hexadecimal and other color codes, what to use to represent the "look" of different temperatures of stars. My problem with that is that they do not take into account the apparent magnitude; they try to use the "magnitude" at the standard 10 parsec distance for all stars. Well, you have to set up
some reference distance to do comparisons, and that's the one in use now. If it were me, I would "move the Sun out to, say, 1 or 2 parsecs and see what its apparent magnitude was, and then say, move any other star to whatever distance from the observer would give it the same magnitude as the Sun at the 1 or 2 pc distance. Then you might be able to compare colors more directly. I just made up the distance; it could be 10 pc or 20 pc. Stars get pretty small at great distances, and discerning color of a "point" source is more problematic. Maybe putting all stars at the distance from the observer where their photospheric or visible disc subtended one arc-second or one arc-minute might be a better test of color, who knows?
Jim