Ok, holy jeezus do I have some responding to do here lol. I am sorry that I started this thread and then didn't get back for ages lol.
First of all, I wanted to stop by and share my maturing views on colour of concentrates.
You guys all know that I've cut my teeth with concentrates predominately using THC bomb. I am familiar enough with the strain to have seen various phenos (more lemon tasting stuff, more diesel tasting stuff etc) as well as material of different maturity.
As some of you might know, I've been pioneering a one-wash complete extraction tech for some time now.
I have found one way to do this, and am working on refining the speed of this process so that no compromises are made.
In my experiments, I have made the extract artist equivalent of my Mona Lisa, an extract of THC bomb that tastes EXACTLY like the plant.
The material in question is an absolute shatter, so hard that I cannot even squash down a large thick chunk between oil slicks with warm hands to thin out the piece. It is like quartz, rock hard shatter!
However, curiously in this, in my experience the most accurate representation of the starting material's flavour/effects without plant material/chlorophyll - I have also found that it is dark, completely see-through, but dark.
Perhaps a warning not to judge our concentrates so much on the colour. IME, I can comfortably say that lighter is not necessarily better when it comes to concentrates. I find the most faithful extractions of some strains can indeed be very dark shatters.
Still, when you squash out a reasonably thin slab, it should be see-through.
Summary: Dark is not necessarily a problem - opaque even in thin slabs is.
I'll be back with more responses soon