Don't know that therre is a correct spelling fo gray/grey, but I believe gray is more commonly used in the U.S. and grey is more common in the U.K.

Also, I think gray is used more when describing something's color, and grey is used to describe the clarity of something. Just my guess.

I think, therefore, I get bananas.

When in doubt, think about time travel conundrums. You'll confuse yourself so you can forget what you were in doubt about.

What's the difference between ignorance, apathy, and ambivalence?
I don't know and I don't care one way or the other.