diff --git a/spacy/displacy/render.py b/spacy/displacy/render.py
index 07550f9aa..984971812 100644
--- a/spacy/displacy/render.py
+++ b/spacy/displacy/render.py
@@ -249,6 +249,12 @@ class EntityRenderer:
         colors = dict(DEFAULT_LABEL_COLORS)
         user_colors = registry.displacy_colors.get_all()
         for user_color in user_colors.values():
+            if callable(user_color):
+                # Since this comes from the function registry, we want to make
+                # sure we support functions that *return* a dict of colors
+                user_color = user_color()
+            if not isinstance(user_color, dict):
+                raise ValueError(Errors.E925.format(obj=type(user_color)))
             colors.update(user_color)
         colors.update(options.get("colors", {}))
         self.default_color = DEFAULT_ENTITY_COLOR
diff --git a/spacy/errors.py b/spacy/errors.py
index be71de820..165714d9e 100644
--- a/spacy/errors.py
+++ b/spacy/errors.py
@@ -476,6 +476,8 @@ class Errors:
     E199 = ("Unable to merge 0-length span at doc[{start}:{end}].")
 
     # TODO: fix numbering after merging develop into master
+    E925 = ("Invalid color values for displaCy visualizer: expected dictionary "
+            "mapping label names to colors but got: {obj}")
     E926 = ("It looks like you're trying to modify nlp.{attr} directly. This "
             "doesn't work because it's an immutable computed property. If you "
             "need to modify the pipeline, use the built-in methods like "