Rather than just showing normal visible images--what you can see with a naked eye--remote sensing can use other bands of light to give a more in-depth sense of what's going on in a scene using variable displays. These false color-images can highlight vegetation, urban areas, or other affects by showing non-visible bands.
You can choose up to three bands to display as either Red, Green, or Blue. These colors will then combine to show the density of reflected light from each band, which combine as shown below.
Then, you'll be able to tell which band is showing at which brightness based on the color that appears, like in a false-color image where you can tell where vegetation is based on brightness of reds.
Radiant.Earth allows you to either set the bands yourself or choose from a number of presets. Which bands are used for each preset is listed below.
In single band mode, only a single wavelength will be displayed, showing the brightness of light reflected at each pixel. This can help with evaluating which bands are present in which areas, or can show differences where only one band is used.
When in Single Band mode, you can choose from a set of color schemes
In custom, you can choose which bands are displayed in which color. This allows you to play with the combinations and display the bands you want. Check out which band corresponds to what wavelengths in Available Bands.
There are also a number of presets available, that automatically choose which bands are displayed, with which bands are shown listed below. At the moment, these presets are only defaulted for Landsat 8 imagery.
You can learn to create your own presets by changing datasource settings.