All the visas types are seem to be classified as "non immigrant" if they are not tourist, if this is the case, is there such thing as an "immigrant" visa and if so who gets it? refugees?

There is a immigrant visa that only immigration can issue. It is issued to holders for permanent residency to allow them to travel. There are a few other special cases where they can be issued but never by an embassy or consulate.

There was an immigrant visa, offered to the BOI for people who applied for permanent residency while abroad based on investment. But this visa is no longer available.

I always wondered about that terminology also.. And assumed that PR people would be the 'immigrants' that fit it somehow..

thanks for clarifying.

There was an immigrant visa, offered to the BOI for people who applied for permanent residency while abroad based on investment. But this visa is no longer available.

An example of this disused type of visa:

There is a immigrant visa that only immigration can issue. It is issued to holders for permanent residency to allow them to travel. There are a few other special cases where they can be issued but never by an embassy or consulate.

It used to be and perhaps still is the case that Thailand has a quota of 100 immigrant visas per year for most countries, only 50 for small countries, with immigrants outside this quota being given a non-quota immigrant visa.

It appears that all foreigners who are given a Certificate of Residence (its colour seem to have changed over the years) get their visa status changed from non-immigrant to non-quota immigrant, even when the annual quota for immigrants from that particular country has not yet been used up. I don't know if a newly approved non-quota immigrant gets an actual visa stamp put in his passport as evidence of his new visa status and if he does I would love to get a scanned copy of such visa as it is still missing in my collection. From a post by a new Permanent Resident I do know that he got this stamp upon approval of his Residency application:

Subsequently, before travelling abroad, a Permanent Resident applies for and receives a non-quota immigrant visa valid for one year for multiple return journeys to Thailand (of which I also have not specimen in my collection)

As far as I know they only do the quotas now for those that are granted PR for each year.