Every registered palette, from ApexMaps.listPalettes(). Click a name to apply it
to the map. The strips show each palette's anchor stops; the class colours the map actually
draws are those stops resampled in OkLab at render time, which is why a
4-class and a 9-class map of the same data stay perceptually consistent, and why ramp midpoints
do not go muddy grey the way sRGB interpolation makes them.
When no palette is named and the data straddles zero, a diverging ramp is chosen, because a
sequential ramp hides the sign: the reader cannot see where the change from negative to positive
happens. The map on the left has data from -40 to 40 and no palette set at all; the
one on the right is the same data forced onto a sequential ramp.
palette: 'blues' · sign is invisible