The color between black and white

Am I the only one who wonders the correct spelling of the color between black and white? I feel like this should be common knowledge, but I find myself getting confused so to put my own (and possible yours) curisiosity at rest, I've looked up the answer. According to the all knowing WikiAnswers both "gray" and "grey" are correct spellings. "Gray" happens to be more popular in the U.S. Because it's the most popular choice, I will be using "grey" from here on out (I'm rooting for the underdog.)

Monochromatic interiors are appealing to me for a couple of reasons. First, I know I could never do it so, therefore, it intrigues me. Second, there's something very soothing about a monochromatic interior. A smart monochromatic space displays variety and interest through different finishes, textures, and pattern. I've tried to find some interesting grey monochromatic spaces because grey exudes romance, mystery, and moodiness. There's so much variety to be had with grey...(hopefully these spaces won't disappear against my background grey!)
This grey leans towards purple...almost. To me, this is a very soothing space.
via Desire to Inspire
A beat up, old chair tells a story if you're willing to listen.
Source: Carolyn Barber {via Desire to Inspire}
The variety of warm and cool greys gives this luxurious space a sense of warmth and depth.
source: House Beautiful {via here}
Pattern lends interest and character to this bedroom.
via LiviaConcept
This is a romantic space from what feels like a different time. The ivory/grey combination is soft yet the textiles and ornate accessories add luxury.
source: Mrs. Howard
I adore the painted floors in this modern, clean room.
source: Gemma Comas via {Grayson: A different shade of grey}
Ok, I cheated a little on this one as the bedspread is obviously purple, but I just adore the grey canopy.
via Marie Claire Maison
This appears to be a well used kitchen and normally bare walls scare me, but I like it here.
source: Roland Bello {via emmas designblogg}
"The color of truth is gray."
-Andre Gide
You don't have to agree with the quote, but it's nice to be comfortable with grey, no?