Well, straight comb isn't part of the standard... Still thinking female... on both. Though the splash is sporting some longer mullet type feathers on the back of the crest... that I would debating/watching as they are so subjective. It might just be father shafts that haven't come off yet or wet feathers. But I don't see ear lobes to well and they are usually easier to see on boys.
I would say nearly all of my males are mating or displaying very boy behavior by your stated age. I never have to second guess boys this long... so if you are second guessing still... probably females.
Your black one is probably blue actually... Silkies are the hardest to tell the two apart (because of the darker tops but the body and solid part of the wings tells a different story)... I thought I had blacks for almost 2 years until I got a black and side by side it is noticeable. Does you blue one have a straight comb too? That one really looks like a pullet as far as I can tell. In fact... if your blue gal WAS a black boy... you would see shiny green tail feathers and a bit on the wings as well.