kirk was blond in tos and i will die on this hill
like y’all know most blonds’ hair darkens over time, he definitely isn’t in the movies but he 100% was when he was younger (plus his hair usually looks gelled, without that it would be even lighter)
Not exactly the matter at hand but as an aside I think it might be possible that Shatner always had darker hair than shown in TOS but that it appeared lighter when filmed. As evidence I bring you Kirk's original uniform, which was green in reality but filmed as yellow because of "a combination of studio lighting, velour material, and the film stock used" and the crew's inexperience with the new colour technology.
It was a technical mistake.
It's worth considering that those same conditions might have influenced how the hair colour appeared on screen vs reality. So I think that to settle the matter once and for all, we should find a coloured non-taken-on-set photo of Shatner from those years.



















