Brown phlegm in the morning?

Question

Almost every morning I spit out a brown phlegm from my throat, which I do not cough (I never have a cough), but it's very thick and slimey and It's the first thing I do in the morning after I wake up. Throughout the day, I still spit out a lot of mucus that feels like coming from my throat, but it's usually white, only the first one in the morning is brown.

Any ideas why would that be? 

I attached a picture so you can see what I'm talking about, it's disgusting, I know.

Update:

Edit: I do not have any accompanying symptoms. I do vape a lot, but I'm not sure if that would be the cause.