Question: When you're meditating, instruction is to focus in between eyebrows and have your eyes still, so while doing that you could have visions, or maybe see colors and it could be very pleasant or your mind could calm down and you're very calm and peaceful. If you are seeing colors or you just feel calm and you're not really focusing between the eyebrows, should you make an effort to come back here?
It's better to remain there (between the eyebrows) until it gets concentrated 100%. Because for a while if it has seen a pleasant vision it gets carried away. For a while it becomes composed, and then it would jump back ferociously, terribly. It's a likelihood. So until and unless it does not learn to remain composed effortlessly, you have to keep watching.
Question: So even if you are seeing beautiful colors and it is very pleasant and you feel very calm?
You keep watching the colors, so that the colors should vanish and the mind should become concentrated without the help of any such vision, on its own. Until then you keep watching. It would be better for you.