prefer -- the one your job uses, the one you believe is industry standard, the
one you think is the One True Standard even though no-one uses it, and so on.
All I ask is that you be internally consistent.
What colour should a normal ethernet cable be?
What colour should a crossover cable be?
Is there a reason that crossover cables should be that colour?
Do you have other standard cat5 cable colours (eg. serial line, temporary patch, trunking, power-over-ethernet)?