colloquial to me, I have seen some series which don´t speak too proper because use a lot of slangs

well, thank you, I will try with them

Colloquial to whom?

FRINGE

Downton Abbey, Penny Dreadful, Elementary, David Attenborough documentaries. Penny Dreadful is a bit scary for some people, so use your discretion :) But I've found the language of the above series to be quite proper.