The Flightmap style editor is a visual interface which enable you to edit and add map styles layer.
You can edit theme by changing the layer property which has full control over various layers. Changing color of water is an example of changing layer property of layer water. The changes made to the layers will reflect on the map.
You can delete the specific layer which you don't want in your map.
Hide/unhide the specific layer from the map.
Select your theme and the same theme will reflect in every screen.