diff --git a/geoviews/plotting/bokeh/__init__.py b/geoviews/plotting/bokeh/__init__.py
index 6f480bca..6f3349c7 100644
--- a/geoviews/plotting/bokeh/__init__.py
+++ b/geoviews/plotting/bokeh/__init__.py
@@ -153,9 +153,10 @@ def get_data(self, element, ranges=None, empty=False):
         dim = element.vdims[0].name if element.vdims else None
         if cmap and dim and element.level is not None:
             cdim = element.vdims[0]
+            dim_name = util.dimension_sanitizer(cdim.name)
             cmapper = self._get_colormapper(cdim, element, ranges, style)
-            data[cdim.name] = [] if empty else element.dimension_values(2)
-            mapping['fill_color'] = {'field': cdim.name,
+            data[dim_name] = [] if empty else [element.level for _ in range(len(xs))]
+            mapping['fill_color'] = {'field': dim_name,
                                      'transform': cmapper}
 
         if 'hover' in self.tools+self.default_tools: