From 72bf994e82553bae4c2075c57db74f44c158c872 Mon Sep 17 00:00:00 2001
From: Ruth Comer <10599679+rcomer@users.noreply.github.com>
Date: Thu, 28 Sep 2023 19:33:48 +0100
Subject: [PATCH] FIX 2-tuple of colors in to_rgba_array

---
 lib/matplotlib/colors.py            | 2 +-
 lib/matplotlib/tests/test_colors.py | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
index 584adba8eace..b9866974d8a3 100644
--- a/lib/matplotlib/colors.py
+++ b/lib/matplotlib/colors.py
@@ -435,7 +435,7 @@ def to_rgba_array(c, alpha=None):
         (n, 4) array of RGBA colors,  where each channel (red, green, blue,
         alpha) can assume values between 0 and 1.
     """
-    if isinstance(c, tuple) and len(c) == 2:
+    if isinstance(c, tuple) and len(c) == 2 and isinstance(c[1], Real):
         if alpha is None:
             c, alpha = c
         else:
diff --git a/lib/matplotlib/tests/test_colors.py b/lib/matplotlib/tests/test_colors.py
index 1c77f995fb53..139efbe17407 100644
--- a/lib/matplotlib/tests/test_colors.py
+++ b/lib/matplotlib/tests/test_colors.py
@@ -1298,6 +1298,11 @@ def test_to_rgba_array_single_str():
         array = mcolors.to_rgba_array("rgb")
 
 
+def test_to_rgba_array_2tuple_str():
+    expected = np.array([[0, 0, 0, 1], [1, 1, 1, 1]])
+    assert_array_equal(mcolors.to_rgba_array(("k", "w")), expected)
+
+
 def test_to_rgba_array_alpha_array():
     with pytest.raises(ValueError, match="The number of colors must match"):
         mcolors.to_rgba_array(np.ones((5, 3), float), alpha=np.ones((2,)))