What I find really interesting is that women can see shades that men cannot. My wife painted several shades of grey on the wall, including "agreeable gray" and I could not tell the difference, all looked the same. I experienced the same thing when she was looking for a grey / green for the kitchen cabinets. I could not tell the difference and all looked grey. She was also able to see shades of blue where all I saw was grey.

I have asked around and I am not the only male in my acquaintances that experiences this.