From the little I know
Amber is natures way of showing that THC is starting to degrade
So, when Amber starts to show, you've taken those buds to the top of the mountain
and it is time to end their expedition there
on the highest peak of their THC journey.
80/20% (Clear/Amber) is the ratio I recall reading several times.
I bought a £5 microscope (X 60 with LED light).
When I first tried using it I thought I'd bought the kind of useless Chinese made tat that goes in a Christmas Cracker or Kinder Surprise Egg
I WAS WRONG
After further attempts I can now see the tiniest downy blond hair on my finger looking like a fibre optic cable
it's a fantastic little gadget and I heartily recommend one to any person who wants to judge the best time to harvest - based on the colour of their plants trichomes.