OMG! I am so sorry. I made a mistake. Well, let me retype it.
1) Spoken English > Written English
2) Formal English > Informal English
3) Colloquial English > ?
I think now it makes sense. I was actually looking for the antonym of "Colloquial". Soothingdave's source helped me to find the answer; which was "formal". I thought there would be any special word. Thank you all.