Blackbody radiation (which even neutron stars will approximate) trends towards a pastel blue as temperature approaches infinity, actually. There is always a sl

Blackbody radiation (which even neutron stars will approximate) trends towards a pastel blue as temperature approaches infinity, actually. There is always a slope in the spectrum in the visible range as the peak is always to the UV/Xray side for very hot objects. "White" light requires that the spectrum be flat in visible wavelengths, which basically requires that the peak be in the visible, which is true for objects at about 6000K. As it happens, the sun is such an object. And it more or less makes sense that we have eyes tuned to pick up the dominant wavelength arriving from our local light source. Edit: the wikipedia page has a great animated chart of this effect, showing what the visible-only spectrum looks like as temperature changes: https://en.wikipedia.org/wiki/Color_temperature https://en.wikipedia.org/wiki/Color_temperature