While it appears white from Earth, that is literally a trick of the light; the question is how it looks from outside.
A comparison of star types in other galaxies gives perhaps an unsurprising result: white. But not just any white: specifically, like spring snow at an hour after sunrise or before sunset.
The finding was announed at the 219th American Astronomical Society meeting.
"For astronomers, one of the most important parameters is actually the colour of the galaxy," Jeffrey Newman of the University of Pittsburgh told BBC News.
"That tells us basically how old the stars in the galaxy are, how recently it's been forming stars - are they forming today or did its stars form billions and billions of years ago?"
Of course, it is difficult to see the Milky Way from the outside, because we are on the inside.
"But it's worse than that; not only are we looking at the Milky Way from the inside, but our view is blocked by dust," Prof Newman told the meeting.
"We can only see about one or two thousand light years in any direction."