you are correct some of those in the pics aren't Silkies.... or at least they are not full Silkie. pink/ red in the bombs is considered a showing/ breeding fault however it doesn't mean that it isn't a full Silkie. ( I have 2 hens with all the correct features who don't have the right coloured combs, for that they are only pets, not for breeding like the rest of my girls) Silkies are slightly smaller and slower to grow however if they start to get normal feathering then they are not Silkies or not 100% pure. however sometimes there is a throwback from previous generations where there was an outcross, so it is possible. Silkies also have a 'walnut' comb so the ones with straight combs are not Silkie, or at least not full Silkie. I hope this helps
