If you have a property called rating
that goes from 0-10, this code will fill in your shape based on it. 1 will be a very light blue, 5 will be a slightly darker blue, and 10 will be even more dark. Numbers in between will be estimated (interpolated). Note that including the 5
level was not necessary - if rating
were 5, MapBox GL would have guessed a color in between the 1
color and the 10
color.
'fill-color': [
'interpolate', ['linear'],
["to-number", ["get", "rating"]],