Need help with Dynamic Lightning

So as a DM i'm trying to learn how to use the Dynamic Lightning, but when I did, the players can see all the map in black and white, even through the walls, while seeing color on their sight. That complicates things, because I don't want them to see the entire map. I've set the gm opacity to max and even tried out one of my players account, but the map continues do be visible no matter what. What am I doing wrong? (Global Illumination is off)

Probably this is Advanced Fog of War. See about resetting the fog of war (in the toolbar at the left).  Probably you put them down before creating the walls and that caused it to be able to "see" the whole map before hand.

It worked.Thanks a lot my kind sir