The real color of the sun is white. The reason that the Sun looks yellow to us is because the Earth's atmosphere scatters higher wavelength colors, like red, orange and yellow less easily. Hence, these wavelengths are what we see, which is why the Sun appears yellow.   The sun emits all colors of the rainbow more or less evenly and in physics, we call this combination "white". That is why we can see so many different colors in the natural world under the illumination of sunlight. If sunlight were purely green, then everything outside would look green or dark. We can see the redness of a rose and the blueness of a butterfly's wing under sunlight because sunlight contains red and blue light. The same goes for all other colors. When a light bulb engineer designs a bulb that is supposed to mimic the sun, and therefore provide natural illumination, he designs a white bulb, not a yellow bulb. The fact that you see all the fundamental colors present in a rainbow and no colors are missing is direct evidence that sunlight is white.