From Here
“When trichomes first form on the cannabis buds and leafs, you will notice they are clear and almost look like they are made of glass. This is the very first stage of their development, and is when they are the least potent.
After a few weeks, you will notice the trichomes start to turn a milky color and look cloudy on the inside. This is when they are full with THC and will give off an energetic high.
After another week or so, the trichomes will begin to turn amber in color, which means the THC is starting to break down into THC-A. The more amber trichomes there are, the more of a couch lock high you will get from the buds.
So, to answer the question of “When is the perfect time to harvest my cannabis buds?”
The answer is really based on your personal preference, and the type of high you would like to receive from your harvest.”