The Sun Is Yellow

The Sun is white. It pumps out light across the whole visible spectrum, fairly evenly, and all those colours mixed together is exactly what white is. Astronauts above the atmosphere see it as a brilliant white disc. The yellow tinge we sometimes see from the ground is the atmosphere's doing: air scatters shorter blue wavelengths away across the sky, which is why the sky is blue, and that subtracted blue can leave the Sun looking a touch yellow, especially when it is low and the light travels through more air, going orange and red at sunset. Classified by astronomers, the Sun is a 'G-type' star, sometimes loosely called a yellow dwarf, which has not helped. But the raw light leaving its surface is white. The yellow is a filter your planet adds on the way in.