Two. Black and white
White (lotsa sports socks), black, brown, grey, tan… and the pair with puppy prints.
What? You can’t tell me you don’t have ONE pair that has puppies, or kitties, or piggies or something on them!
I have mostly black and white socks. I was given a pack that had a pair each blue, gray and red, and I bought a pair of olive green ones to go with a particular outfit. But like I said, mostly black or white.
I’ve got a lot of different colors: red, blue, green, tan, white, black, etc. Most of them are ankle-length, with a small assortment of longer ones.
Most of the colors I picked up because I’m cheap when it comes to socks. How cheap? I usually pick them up on clearance, when they’re knocked down to a buck or two for a three-pack. And usually three-packs of a single color (much less packs of just white or black socks) don’t last long enough to make it to the clearance rack. Because I now rarely wear anything other than boots of some persuasion, you never see what color socks I’m wearing.
Unless you happen to be near me when I’m going through airport security. 
<< Don’t hate yourself in the morning–sleep till noon. >>
All of my socks are white except for a couple black pairs. When I buy socks, I try to buy a large package of them so I can quickly dig out a matching pair from the drawer without having to pair them when they come out of the dryer.
Three. White, black, and the gray ones that were white but slipped in with a non-colorfast item.
Mostly black or white. I have one pair of dark grey, one pair light grey, and one pair khaki.
Two…white for everyday, black for work.
Brendon
White work sox. Black, blue, or brown dress sox, to match the suit.
In practice, one. In fact, just one brand: Marks Work Wearhouse size 12-14 tan sports sock.
I suppose if anyone else made sturdy size 13 socks I’d try them, but with these I can put them in with whatever colour of washing I have, and they end up coming out more-or-less the same colour that they went in. That also means that if I ever need more, the new ones look just like the old ones, so all my socks match each other.
Black, brown, and white. I wear the black ones most often as I usually wear black pants to work and wear them with jeans when I’m wearing black shoes. The white ones are mainly for workouts. The brown ones match khaki pants which I’ll wear to work during the summer.
Black. White. Green.
Four: White socks (lots and lots of white socks) that I buy for myself. Purple/pink fuzzy socks that my sister got me for Christmas. Blue/black/maroon-y-red striped toe socks that my sister got me for Christmas. Red/green/white snowman socks that, yes, my sister got me for Christmas.
Black, white, grey, & maybe a couple of others in the back of the drawer that I don’t wear.
Multiple colours. Most of my socks are stripey or have polka dots or pictures on them. My favourite ones are my stripey socks with Tiger on them. I really need to buy some black ones because I crossed my legs in the hospital last week and realised the skulls on my socks were showing. My socks are often mismatched because I never sort them after laundry.
Dark blue, a pair of light blue (dunno why), white, mainly black, some a browny mix. There’s a pair of red socks around here somewhere from when we were all mad on the America’s Cup thing, but they’re definitely the exception.
Two: Black and white.
I probably have 20 pairs of white socks and 1 pair of black ones
One: Gray.
I have only black socks, except for a few pairs of white socks for when I’m exersizing.
Two: black and white.
I finally got fed up with trying to match together so many similar-looking socks and realizing partway through the day that I was wearing one semi-thick dark navy blue sock and one slightly thinner gray-black sock with a seam down the side.
The solution: I declared a sock purge. Any and all socks were hunted down, rounded up in bags, and thrown away. Dark, light, new, worn, big, small, winter, summer, none survived. Then I headed down to the local Uniqlo, found white socks and black socks in my size, and bought ten pairs of each in exactly the same style. By selective purchasing that eliminates individual styles, my sock drawer is now free from the conflict and strife that inequality between the soxes inevitably breeds. Socks are no longer confined to set pairings, instead joining freely and openly with new partners as each day sees fit. The old and infirm are quietly removed and replaced by a new generation, while the system of open pairings eliminates the loneliness of widows and orphans.
Oh, brave new drawer that has such socks in it!