During the documentation build for the release `0.11.0`, the [Instrument Trajectory > Instrument field of views](https://moon-coverage.univ-nantes.fr/en/0.11.0/trajectory/instrument/fovs.html) page failed to build correctly due to missing color getters. This is due to a change of `get_facecolors()` to `get_facecolor()` in `moon-coverage.projections.proj.Projection.xy_collection()` in 5bc4b8ac. This change was not propagated to `FovsCollection` and was not covered by our test suite.