I recently picked up some over-the-calf navy socks from Kabbaz-Kelly & Sons and The Hound Clothiers. Navy, as you’ve read a dozen times by now, is the easiest color to wear, and that holds equally true for socks as it does for sport coats. You can wear these with almost any color of trousers and not give the matter too much thought in the morning.
I can only think of a few exceptions. Sometimes, lighter colored trousers, such as tan or light grey, seem to pair better with similarly colored socks or at least something that matches the day’s shoes. For example, last week I wore a navy wool sport coat, light blue shirt made from an end-on-end cloth, sand linen trousers, and a pair of dark brown derbies. Navy socks here made the trousers look a little lost for some reason, so I put on a pair of dark brown socks and things looked a bit more balanced.
For some bit of a visual interest, a few of my socks feature subtle, conservative patterns. Above are pin dots and herringbones by Marcoliani, and a pair of “slash fashion herringbone” by Bresciani. Marcoliani’s herringbone borders on slightly too bright, but I think they still work with slightly more casual ensembles. The others are dark and subtle enough that they could work with almost anything except a business suit. I wear these under dark olive glen plaid, charcoal windowpane, and plain mid-grey flannel trousers. I think they’re a nice way to have fun with your socks without crossing over into wacky.
If you’re on the market for such dress socks, I highly recommend Marcoliani and Bresciani. They’re a bit expensive, but from my experience, also the best made anywhere. A more affordable alternative is Pantherella, which comes up on Gilt and Sierra Trading Post for about $7-12 a pair every so often. Just make sure you get over-the-calf versions. They don’t slip down, so they’ll never expose your bare, pale calves when you sit down or cross your legs. That, in my opinion, should always be a requirement of dress socks.