Why?
Isn’t it actually grey?
No.
Look at moon.
Look at something grey.
Compare.
Clarity ensues.
The term “grey” is a relative issue.
From this site
The newer the soil, the higher the degree of brightness ( reflectivity ) is found in lunar soil.
A futher note on what exactly the lunar albedo is:
So, it may be grey (or gray) in color but due to the contrast ratio of the sunlight striking the surface of the moon compared to the total non-reflective nature of the space around the moon, by comparison the surface appears quite bright overall and very bright in some areas of the surface. ( See the first link as to why there are gradations, etc. ).
Having stood in the Lackawanna Coal Mine in Lackawanna, Pennsylvania I can say that anthracite coal is pretty sparkly when in pulverized form. The surface of the moon is not akin to corn starch, it’s fairly coarse according to firsthand reports from astronauts. Therefore, like pulverized anthracite, there is some sparkle going on there. 12 % of the sunlight striking it apparently is a hell of a lot of sunlight. 
Cartooniverse
( shoulda added this above, sorry for the doublepost )
And as a personal aside, I grew up looking at very high quality color images of the surface of the moon. Many of them were never published. Daddy was a science writer for a large metropolitan newspaper and was given copious press kits by NASA on each and every trip to Houston.
The fact that the surface of the Moon is indeed gray is beyond argue. It is not white, by any stretch of any color scale used on Earth. However, as explained above, the native gray color of the dust on the surface doesn’t stop it from appearing as white or near-white to our eyes.
The few Moon rocks on public display are not white. They are varying shades of gray.
What a coincidence that this topic came up. I just read a book review that quotes a former moon-visiting astronaut. He comments that the moon is, in fact, gray, but “until you’ve been there, you have no idea how many shades of gray there are.”
I thought it was green, like the cheese it’s made of. Shows what an education one gets from this board.
Colors are perceived differently compared to what is around them. (Like that picture of the checkerboard in shadow.) If you take something gray, and surround it by a very intense black like the night sky… it has a tendency to look brighter and whiter.
That’s the same logic that, when viewing the moon in the daytime, made man once think the moon has seas. You will observe that the moon, in the daytime sky, appears to have blue patches where the larger craters are. Although, just why this happens I’m not sure, and it’d be a whole other thread… (hint, hint).
Let’s do a little thought experiment…
Imagine two copies of the moon in the sky, one being the identical moon we have today, the other an exact copy with the only difference being it is bright white in actual color. What do we see from earth? Our old, familiar moon doesn’t look so white anymore next to the white-moon. In fact, the new white-moon is so blindingly white… next to the old gray-moon, you wonder how you ever thought it could have looked white to you in the first place.
Personally, I always think of the moon as more of a pale yellow. shrugs
Vastly oversimplifying, the human visual system tends to adjust itself to perceive the brightest object in view as white, so even though it’s only bright greay, it’s (often) the brightest thing you can see at night and so your ‘white balance’ accepts it as white. If you were an astronaut standing on the surface of the moon, you’d be able to perceive it as grey because your white space suit gloves would be the brightest thing in view.
“Hmmm…it doesn’t taste like any cheese I’ve ever had.”
Stranger
Wensleydale?