To explain this further man, cannabis varieties ('strain' is NOT any kind of botanical classification relevant to cannabis and is stoner lingo, not science - IIRC in science 'strain' is a term used in virus taxonomy! lol) have many phenotypes (variety within 'varieties' if you will).
What this means is sometimes a single variety (mistakenly called strain) can have multiple expressions, often between 2-5 phenotypes and maybe more in some cases. Some of these phenos might be purple. Some of them might be plain old green. Some of them may taste radically different from other phenos of the same variety.
For this reason (also many others, including how the plant was grown etc), you can't rely on the same 'strain' having the same smell/taste/appearance all the time - nor should we be surprised to find this given that 'strain' is not a scientific term relating to plant phylogeny/taxonomy and does not describe discrete botanical varieties.
My advise is to consider the chemotype (chemical profile) and/or both the variety (which is the term in the literature used for 'strain name') and phenotype of a given sample of cannabis material; not the 'strain', if you want to understand the nature of the material you have more fully in a way that better distinguishes different material. A few of the seedbank type sites mentioned above will outline the known phenotypes that are observed within a given variety which is one of the few sources of information where this can be found atm.
Man I'd kill for a taste of '70's vintage Columbian Gold (was like smoking honey).
