From a5b34a82def54532e97a12b284450b39991dddc8 Mon Sep 17 00:00:00 2001
From: Miro <200482516+Mirochill@users.noreply.github.com>
Date: Mon, 25 May 2026 20:51:27 +0200
Subject: [PATCH] Support RGBColor shorthand hex strings

---
 src/docx/shared.py   |  7 ++++++-
 tests/test_shared.py | 12 ++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/docx/shared.py b/src/docx/shared.py
index 6c12dc91e..21313f868 100644
--- a/src/docx/shared.py
+++ b/src/docx/shared.py
@@ -142,7 +142,12 @@ def __str__(self):
 
     @classmethod
     def from_string(cls, rgb_hex_str: str) -> RGBColor:
-        """Return a new instance from an RGB color hex string like ``'3C2F80'``."""
+        """Return a new instance from an RGB color hex string.
+
+        Supports six-digit values like ``'3C2F80'`` and three-digit shorthand like ``'F00'``.
+        """
+        if len(rgb_hex_str) == 3:
+            rgb_hex_str = "".join(char * 2 for char in rgb_hex_str)
         r = int(rgb_hex_str[:2], 16)
         g = int(rgb_hex_str[2:4], 16)
         b = int(rgb_hex_str[4:], 16)
diff --git a/tests/test_shared.py b/tests/test_shared.py
index fb6c273cb..cc4de7170 100644
--- a/tests/test_shared.py
+++ b/tests/test_shared.py
@@ -113,6 +113,18 @@ def it_can_construct_from_a_hex_string_rgb_value(self):
         rgb = RGBColor.from_string("123456")
         assert rgb == RGBColor(0x12, 0x34, 0x56)
 
+    @pytest.mark.parametrize(
+        ("rgb_hex_str", "expected_rgb"),
+        [
+            ("123", RGBColor(0x11, 0x22, 0x33)),
+            ("aBc", RGBColor(0xAA, 0xBB, 0xCC)),
+        ],
+    )
+    def it_can_construct_from_a_three_digit_hex_string_rgb_value(
+        self, rgb_hex_str: str, expected_rgb: RGBColor
+    ):
+        assert RGBColor.from_string(rgb_hex_str) == expected_rgb
+
     def it_can_provide_a_hex_string_rgb_value(self):
         assert str(RGBColor(0xF3, 0x8A, 0x56)) == "F38A56"