Now that you have set the styles that you want for raster and vector layers, you will likely want to save the styles so that they can be used again later or applied to other layers. There are four buttons that are used to manage styles. These four buttons, shown in the following screenshot, are always displayed near the bottom of the Layer Properties window:
In this section, we will use these four buttons to save a style to a style file, load a saved style file, and set and restore a default style.
QGIS can save styles in two file formats: .qml and .sld. The .qml style file is specific to QGIS, while the .sld style file is useable by other programs to style files. In general, you should plan on saving styles using the .qml file type as it does the best job of saving your styles; however, if portability is a priority, then the .sld file is the better choice. To save a style, open the Layer Properties window, set the style that you wish...