Our Milky Way galaxy and its neighbor, the Andromeda galaxy, seem to be going through a midlife crisis.

New research reveals that both galaxies are in the middle of transitioning from young, star-forming regions into older, stagnant ones, a transition that is revealed by the galaxies' color. Generally, such a change comes after two galaxies collide, astronomers said, but this pair seems to be making the shift on its own.

In galaxies, star formation rates and color are closely related. But, analyses of the shade of the Milky Way are surprisingly rare.

Instead of the young, active signs they expected, the astronomers determined that both galaxies are not the typical blue or red color, but instead, fall in an in-between state of green.

Scientists have long regarded the Milky Way as a "typical" spiral galaxy, but in regards to color, the galaxy doesn't quite follow the standard model.

"Green galaxies are commonly thought to represent galaxies which are undergoing the transition from being young, dynamic, energetic, star-forming blue galaxies to being old, lethargic red galaxies," Mutch told SPACE.com in an email interview.

"In terms of a human being, this transitional phase could be thought of being akin to a midlife crisis."

So, why is the Milky Way running out of dust? Mutch isn't sure.

Sometimes black holes will inject large amounts of energy into the surrounding region, Mutch explained. This keeps new gas from being accreted.

"However, we know from observations that the central black hole of our galaxy is not particularly active," Mutch said.

The new color "provides us with an interesting open question as to what exactly is causing the Milky Way and Andromeda to be running out of fuel for producing new stars."