From f02b90b401808bfb4f0f555fb7fa1cc21ed8334d Mon Sep 17 00:00:00 2001
From: dcherian <dcherian@mit.edu>
Date: Tue, 20 Feb 2018 08:59:57 -0800
Subject: [PATCH] facetgrid: unset cmap if colors is specified.

---
 doc/whats-new.rst         |  2 ++
 xarray/plot/facetgrid.py  | 11 +++++++++++
 xarray/tests/test_plot.py |  4 ++++
 3 files changed, 17 insertions(+)

diff --git a/doc/whats-new.rst b/doc/whats-new.rst
index 8b200103303..e2baa05fbc7 100644
--- a/doc/whats-new.rst
+++ b/doc/whats-new.rst
@@ -43,6 +43,8 @@ Bug fixes
 
 - Fix the precision drop after indexing datetime64 arrays (:issue:`1932`).
   By `Keisuke Fujii <https://github.com/fujiisoup>`_.
+- Fix kwarg `colors` clashing with auto-inferred `cmap` (:issue:`1461`)
+  By `Deepak Cherian <https://github.com/dcherian>`_.
 
 .. _whats-new.0.10.1:
 
diff --git a/xarray/plot/facetgrid.py b/xarray/plot/facetgrid.py
index badd44b25db..fd94439db4f 100644
--- a/xarray/plot/facetgrid.py
+++ b/xarray/plot/facetgrid.py
@@ -221,6 +221,14 @@ def map_dataarray(self, func, x, y, **kwargs):
         self : FacetGrid object
 
         """
+
+        cmapkw = kwargs.get('cmap')
+        colorskw = kwargs.get('colors')
+
+        # colors is mutually exclusive with cmap
+        if cmapkw and colorskw:
+            raise ValueError("Can't specify both cmap and colors.")
+
         # These should be consistent with xarray.plot._plot2d
         cmap_kwargs = {'plot_data': self.data.values,
                        # MPL default
@@ -233,6 +241,9 @@ def map_dataarray(self, func, x, y, **kwargs):
 
         cmap_params = _determine_cmap_params(**cmap_kwargs)
 
+        if colorskw is not None:
+            cmap_params['cmap'] = None
+
         # Order is important
         func_kwargs = kwargs.copy()
         func_kwargs.update(cmap_params)
diff --git a/xarray/tests/test_plot.py b/xarray/tests/test_plot.py
index 46410cd53e3..672a9e4a579 100644
--- a/xarray/tests/test_plot.py
+++ b/xarray/tests/test_plot.py
@@ -902,6 +902,10 @@ def test_facetgrid_cmap(self):
         # check that all colormaps are the same
         assert len(set(m.get_cmap().name for m in fg._mappables)) == 1
 
+    def test_cmap_and_color_both(self):
+        with pytest.raises(ValueError):
+            self.plotmethod(colors='k', cmap='RdBu')
+
 
 @pytest.mark.slow
 class TestContourf(Common2dMixin, PlotTestCase):