Color land and water

The land and water arguments of pygmt.Figure.coast specify a color to fill in the land and water masses, respectively. You can use standard GMT color names or give a hex value (like #333333).

import pygmt

fig = pygmt.Figure()
# Make a global Mollweide map with automatic ticks
fig.basemap(region="g", projection="W8i", frame=True)
# Plot the land as light gray
fig.coast(land="#666666", water="skyblue")
fig.show()