As far as i know, there is no blue hat SEO but I know there are two types of SEO: White Hat and Black Hat. Besides Gray hat is also remain. But never i am hear about bule hat SEO activities and how it does work?
I’d say that about sums it up. There are lots of Google hits for every different color of SEO, but it’s all nonsense. There is basically White Hat and Black Hat SEO. (And even these two are just subdivisions of one overall category, known as In Your Hat SEO.)
There is no “healthy mix” of Black Hat and White Hat SEO. Black Hat techniques aim to manipulate rankings in ways contrary to the search engines’ guidelines, or by deception and your site may well be penalised as a result.