With some hardware and software using more than 32 bits to store colour values, it's now possible for everyone on the planet to have their own personal colour.
Assuming 64 bits per colour value, we could each have 3 billion colours. The world population is bound to increase, but it should be safe to assume we could each reserve a million colours.
Seeing as I spoke first, I'll take 0x0 up to and including 0xF423F. You can fight over the rest.