Dark purple / black trichomes

Hi, anyone ever see black or dark purple trichomes at 6 weeks flowering for a 8-9 week strain (Strawberry Lemonade)? Pics show stem and some tric heads r deep purple or black. Doesn’t seem like dirt and no sight of insects….
New here in the forum. Hope to get some ideas from experienced grower.

Calyxes are not full but about half of trichomes are turning amber. The plants are too early to be harvested.
The plants have been spending about 6 hours a day under direct and strong southern cal sun. Not sure if the resin /trichomes are burnt.

Genetics, as far as I can tell. I dig those purple plants. Definitely looks to have a while to go still.

Thank you much. Worry about too much Sun cooking it Cajun style!
I will wait for it to finish based on other signs.