The sun is actually white, it's the earth's atmosphere that makes it appear yellow

Much like the sky not actually being blue, the sun is actually not yellow (or orange, if you catch it at dusk or dawn). Earth’s atmosphere refracts light, making things outside of it appear different colors. For the sky, that color changes from black to blue as the sun’s light refracts through the atmosphere. For the sun itself, it changes color from its actual white to a yellow or orange color as light refracts through the atmosphere.