From c368e89577ab9072f3fe7216861d766f30c73f79 Mon Sep 17 00:00:00 2001
From: robertoffmoura <robertoffmoura@gmail.com>
Date: Fri, 18 Jul 2025 16:11:33 +0100
Subject: [PATCH] Set plot_bgcolor to white by default when converting from
 matplotlib figure

---
 plotly/matplotlylib/renderer.py            |  1 +
 plotly/matplotlylib/tests/__init__.py      |  4 ++++
 plotly/matplotlylib/tests/test_renderer.py | 11 +++++++++++
 3 files changed, 16 insertions(+)
 create mode 100644 plotly/matplotlylib/tests/__init__.py
 create mode 100644 plotly/matplotlylib/tests/test_renderer.py

diff --git a/plotly/matplotlylib/renderer.py b/plotly/matplotlylib/renderer.py
index e05a046607a..8878695ffe1 100644
--- a/plotly/matplotlylib/renderer.py
+++ b/plotly/matplotlylib/renderer.py
@@ -85,6 +85,7 @@ def open_figure(self, fig, props):
             autosize=False,
             hovermode="closest",
         )
+        self.plotly_fig["layout"].template.layout.plot_bgcolor = "white"
         self.mpl_x_bounds, self.mpl_y_bounds = mpltools.get_axes_bounds(fig)
         margin = go.layout.Margin(
             l=int(self.mpl_x_bounds[0] * self.plotly_fig["layout"]["width"]),
diff --git a/plotly/matplotlylib/tests/__init__.py b/plotly/matplotlylib/tests/__init__.py
new file mode 100644
index 00000000000..c29e9896d61
--- /dev/null
+++ b/plotly/matplotlylib/tests/__init__.py
@@ -0,0 +1,4 @@
+import matplotlib
+
+matplotlib.use("Agg")
+import matplotlib.pyplot as plt
diff --git a/plotly/matplotlylib/tests/test_renderer.py b/plotly/matplotlylib/tests/test_renderer.py
new file mode 100644
index 00000000000..f46ecb796f7
--- /dev/null
+++ b/plotly/matplotlylib/tests/test_renderer.py
@@ -0,0 +1,11 @@
+import plotly.tools as tls
+
+from . import plt
+
+def test_plot_bgcolor_defaults_to_white():
+    plt.figure()
+    plt.plot([0, 1], [0, 1])
+
+    plotly_fig = tls.mpl_to_plotly(plt.gcf())
+
+    assert plotly_fig.layout.template.layout.plot_bgcolor == "white"