The surface of the sun is about 5750 K. This leads to color around #fff0e9, while the actual color of the sun is #fff5f2. Outside the atmosphere
, the color of the sun is #fff3ea, while from the surface
, through the atmosphere, the color is about #fff5f2. There is some scattering
taking place (#fff5f2 - #fff3ea): 2 units of color in green, and 8 units of color in blue. The atmosphere does make color of the sun a bit "warmer" than it really is.
The color of a blackbody between 5000 and 7000 K is nearly white, to us. That "to us" is an important consideration - our eyes have evolved to perceive the world in the strongest segment of the blackbody radiation for the sun, and thus we regard it as 'white'. If you ask an insect (which has vision balanced in the UV) the the bee would claim the sun is redish, while asking a creature that has color pushed in the red direction would consider the sun to be bluish.
The color of the daylight sun is certainly not that of sunflower yellow (#ffff00), but rather much closer to a light yellow (#ffffe0).
Much of the question of "what color is that" depends upon the answer to the question "what color is white?". The the definitions of colors are based upon the question of a white point. There are 3 of the standard versions used that are : D65, D50, and B. The "D" series of color was introduced in 1963 by CIE to represent the color of "daylight" at different color temperatures. D65 is typically used (and has been used to give the above color values). The '65' and '50' parts of the color scale refer to
the color temperature of 6500 K and 5000 K respectively. More information on this can be found in the Color FAQ (url below), sections 15 and 16.
Part of our image of the sun comes from the times when we can view it without blinding ourselves. Most often, this is the sunrise and sunset where the atmospheric scattering (and pollution in it) becomes a much more important factor. During the sunset, the sun does indeed appear to be a much deeper red, orange, or yellow. These are the images of the sun that we have and recall when asked "What color is the sun?".
http://www.vendian.org/mncharity/dir3/starcolor/ (Color values above are from this set of pages)