Leg color, while often an indicator of gender in Barred Rock chicks, is far from infallible, particularly where hatchery quality Barred Rocks are concerned. Your chick is too young at this point to sex accurately. When his barred feathers fully come in (around 6 weeks or so), if it is a male it will have light barring, and if it is a female it will have dark barring. As it matures, if it is a male, it's comb will redden as well. If it is a female, its comb will not redden until it is almost ready to lay. I would suggest posting your chick's pic again in about 5-6 weeks. By then its gender should be obvious.