Nor is there really a dark side or light side of the force. There is just the user and their intent.
There is no light side of the Force, but there is a dark side.
There's the Force, and an aspect of the Force that is called its "dark side". The dark side is a corruptive force, and denying that it is an actual thing is rather silly.
Well it depends upon your definition of grey, the proper grey balances light and dark, but Revan at that point was transitioning between the two sides (not that this was his intention), which is not the same. But you could make an argument for either viewpoint.
Like balancing between being healthy or stricken with cancer...