If you are traveling in a primary channel and you encounter a red and green marker (with the green band on top) when proceeding in an upstream direction, what must you do

There are many indicators used in navigation such as international markers in order to understand quickly the directions intended during sailing. For example, a green marker indicates that you must pass on the side such that the green marker will be on your left side while the red marker means that the marker should be on your right side on the other hand upon passing the marker. Now when there is a green and red marker, this means you can either pass on either sides but the recommended channel is the direction indicated by the color of topmost band. If green, the navigator must work so that the passing makes the marker on the left side.