Originally Posted by jewhitehead
The dealer told me this was gray water low point, which I thought was odd. Still trying to learn the in and outs of this while rv thing.
It always helps to tell everyone what brand and model of trailer you have when asking questions.
In your picture, as others have said, the blue is the cold water drain and the red is the hot water low point drains. Also in your picture it looks like the fresh water holding tank drain. There might also be a fourth hose that isn't capped and that would be your fresh water tank overflow tube.