How do I get rid of gray around these models?

I am very new with this, and I was wondering how to fix. The gray areas around the water, waterfall, etc are what I need gone! Thanks!


it looks like your tiles are having a transparent background. In that case you need to put them into a second layer above your ground tiles. Otherwise the tiles you place over the first layer replace the tiles in that layer and you end up with transparent tiles without anything below (resulting in gray spaces on the map in tiled).