I unmolded my nw batch a couple days ago and no sign of white streaks!! so happy

The only thing was that the batch was lighter on the outside, when I cut it into bars I noticed it was a little darker in the inside and each bar has a lighter layer around it about 2mm.
any idea why?
If it didn't gel completely how can I prevent it from happening again? I always leave my soap in the mold for 12-14 hours, I've
left my soaps for 24 hours but usually ended up with something like "alien brain". I don't know why but I think it might be the dry weather.
I always cover the mold with a plastic wrap and wooden lid and a blanket.