i think it's also light distance. blurple LED burn looks like that and i've had multiple grows where despite knowing this i misidentified it as natural purpling and other deficiencies/pH problems at same time.
Good object lesson on how little power the plant actually needs to draw from its leaves in order to bloom per cola, hence most growers defoliate heavily during flowering. The hormones carried it this far.
That's also why the top is purple, most likely -- all the bits that dont reflect purple have been cooked off. If that's what it was, you'll know because the buds will be less spongey and more dry in the more purple areas near the surface (and top of the plant).
We've pretty much all burned some plants, so it's no big deal. You still get good yield per its size with this plant =)
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