Add a border to clarify the boundary of the image.

bdice · bdice · commit d62cd5558419 · 2020-07-11T12:28:00.000-05:00
diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
@@ -711,6 +711,7 @@ def _repr_html_(self):
                 '<img ' +
                 'alt="' + self.name + ' color map" ' +
                 'title="' + self.name + '"' +
+                'style="border: 1px solid #555;" ' +
                 'src="data:image/png;base64,' + png_base64 + '">')
 
 
