Not so fast. Sock magic: I've only bought black socks over the last 5 year, and still I can't seem to find ones anymore that exactly match in both fitting and color (they all seem to have degraded in different color tones)
(Source: Am a fellow black-sock-only person who made the above mistake last time around.)
Mitigation might include not washing any socks until all clean pairs are exhausted, but this may result in a smelly linen bin. Alternatives might be keeping clean socks in a pair of tights with the toes cut out - most recently cleaned in the top pushing down, fresh pairs taken from the open toe; hang this up for a better UX.