I’m not successful in determining sex based on combs with the rose comb. In fact, there are very few breeds where I use the comb to judge.
With SLW in particular, the males will start to develop those lighter colored neck feathers, and of course the saddle feathers will tell you for sure later.
Obviously, there are tons of people who swear that the early reddening of the comb happens with males. But I believe that isn’t always the case.
Seen a lot of males with barely pink combs, seen a lot of girls with pretty visible combs. My boy was reasonably easy. I guessed he was male by the first week. I knew it by week two. Here he was at about 2 weeks.
His comb was pretty well developed.
When his feathering came in it was a lot easier to see he was a boy. His shoulders got a lot of white, and his pattern was a bit mashy.
Red wattles at an early age are also a sign of being male--I often prefer to look at the wattles instead of the comb, because I find it easier to spot the gender differences there.