I won't presume to know what is generally accepted, but man - we're stoners. The consensus of the stoned (or even sober) masses does not equal accurate information
That's why I'm only interested in the scientific, empirical information on the topic.
I will say that if you have got only actives in your conventional solvent based concentrate, it is gonna be either absolute shatter, or if decarboxilated, some point in between this and a runny but clear nectar/oil consistency. Expect various hues between almost clear pale yellow, amber, red and variations on these colours (depends on strain/terp profile and other factors - ie: ethanol seems to give a red tinge to concentrates).
IME, wax necessarily contains plant waxes. That is the only way I know of to get an actual wax consistency (even stuff with residual solvents is not so much wax as it is some kind of grease type consistency which is a bastard to get off your oil slicks). I have dabbed pure plant wax as was mentioned earlier. It is hot, harsh and wax concentrates always make me feel congested as fuck (however dabbing any inactives will likely contribute to congestion). IMO you don't want that in your dabs if you can avoid it. Still, it isn't like poison like gluten or something [/South Park].
Clear but Green/black/super dark brown concentrates generally are a visit from our friend chlorophyll, but I cannot rule out some other possibilities contributing dark brown hues as well.
Anything runny and slick that sticks to oil slicks and seems to just spread across the oil slick as you try to scoop it on a dabber is almost definitely full of residual solvent.
Hope these pointers help!
Non see-through concentrates contain a lot more inactives which can include but are not necessarily limited to; solid particulate plant material, high plant wax content and high levels of chlorophyll IME.
Of course, a very high purity (high up in the 90th percentile of glandular resin heads) dry sift extract will look like dry, white-ish to amber coloured crystals.