Naked neck Silkies are known as Show girls (even the roosters)... and the grey color is technically called Blue in chickens.
I don't see anything screaming cockerel just yet. Great job on those technical terms BTW!
8 weeks is still a tad young and could be a late bloomer in addition to features that are still coming in. I am seeing some hints of red in the lower wing area that might be pointing to cockerel. Without any behaviors or siblings for comparison... hard to give a solid answer. I'm going with *possibly* pullet.
I bred and raised Silkies for a few years. It's hard to imagine but some lines can be so different than others.
Thank you for responding to my comment. I have a white Polish silkie mix who grew up with my naked neck silkie since they were chicks. I’m not sure the gender of that chicken either but here is a picture with them together.