Hey Art, thc is naturally clear. By this, I mean really clear. No color at all to it when it's freshly made. You can see right through it.
At near-life-end for MJ plants, the thc containing resins of the plant start degrading. The first sign of this degradation is when the resins turn cloudy. Instead of a perfectly clear tiny drop of wonder, you won't be able to see through it. It looks hazed to opaque like a frosted window. Still white colored, but hazed or cloudy.
Then, when it degrades some more, it starts turning yellowish. You'll first see a very slight discoloration that almost isn't there. Then, as the days go by, you'll see them turn darker and darker "Amber" or golden colored.
When the resins are perfectly clear, the thc is at it's most psychoactive.
When it's turned very, very dark brown, it won't get you high at all. It's dead.
Between those two points, it goes from Clear to hazed, to real cloudy to totally opaque to totally opaque with a slightly yellow tint to more of a darker yellow tint to gold to really dark gold to slightly brown to real brown.
I prefer my weed at harvest to be part clear, about half cloudy and about half light gold.
Keep in mind that this is an AVERAGE OVER THE ENTIRE PLANT. You might have one area that's all gold and another that is all clear. For the most consistent high, take one branch at a time, starting with the one that is perfect for your preferences. Then, as the next few days pass, harvest each branch as it reaches that same point of coloration.