Alex stood in front of a mirror observing himself.

“What color?”

he inquired of no one in particular.

A vintage photo of Marilyn Monroe altered for different colors to appear differently in three ways

Getty Images

He stared at his reflection a little longer before repeating the question: “What color?”

Alex was a gray parrot purchased from a pet shop by psychologist Irene Pepperberg in 1977.

To date, Alex is perhaps the only animal to ask a seemingly existential question.

a vintage photo of marilyn monroe posing on a diving board with one leg pointed down toward the water

Bettmann/Getty Images

And how do you describe blue to someone who’s never observed it?

For most, these debates arise only in Philosophy 101.

Actually, those with color blindness still usually see plenty of color, they just experience it differently.

a vintage photo of marilyn monroe posing on a diving board that has been altered to show how someone with colorblindness…

Greens may appear muted.

Remember how we said it was genetic?

But biology is not the only contributor.

a vintage photo of marilyn monroe posing on a diving board that has been altered to show how someone with colorblindness…

We took an image ofMarilyn Monroe (upper left) and used a digital simulator to show how different types of color blindness might impact the way you see it  —  though “it’s impossible…to fully appreciate what color deficiency might look like in any specific individual,” says the Mayo Clinic’s Schornack.

Also consider the case of Claude Monet.

(Yes,thatMonet.)

“It’s like when you go skiing and you wear those yellow-tinted glasses.

a vintage photo of marilyn monroe posing on a diving board that has been altered to show how someone with colorblindness…

We took an image ofMarilyn Monroe (upper left) and used a digital simulator to show how different types of color blindness might impact the way you see it  —  though “it’s impossible…to fully appreciate what color deficiency might look like in any specific individual,” says the Mayo Clinic’s Schornack.

Maybe the grass isn’t always greener (or reddish-greener) after all.

More on color:

Now check out 100 years of hair color: