Good morning Army. 70 today, but rainy.
Daniel, it is normal for most juices to darken or change color. Few don't (Dark Horse is one example). Two week HA is good to go. It will continue to steep beyond that but its still good at two weeks. Everyone is different.
The industry (Manufacturers) even have a name for it called... "Tanning". I have read that it is from exposure to light but mine does it in a dark closet (Tanning that is).

