Hi,
If these are just ordanary chicks, your not going to be able to sex the chicks until they are at least 8 weeks old.
At 8 weeks old, the young male's comb will start to get more redder, and grow slighly faster than a young pullet. Pullets combs are gernerally a yellow/buff colour.
Also around this time, young males have got longer legs, giving them a more upright posture.
As for a above methods, The colour of the chicks unless sex linked breeds has no effect on sexes!
You can only measure wing feather lengths on broiler breeder chicks, no other breeds!
You can not vent sex