diff --git a/src/libraries/Common/src/System/Drawing/KnownColor.cs b/src/libraries/Common/src/System/Drawing/KnownColor.cs
index 2608f2e5f3d89e..0ad4da86e4e13e 100644
--- a/src/libraries/Common/src/System/Drawing/KnownColor.cs
+++ b/src/libraries/Common/src/System/Drawing/KnownColor.cs
@@ -197,6 +197,9 @@ public enum KnownColor
         MenuHighlight,
 
         // "Web" colors, Part 2
+        /// <summary>
+        /// A system defined color representing the ARGB value <c>#663399</c>.
+        /// </summary>
         RebeccaPurple,
     }
 }
diff --git a/src/libraries/System.Drawing.Primitives/src/System/Drawing/Color.cs b/src/libraries/System.Drawing.Primitives/src/System/Drawing/Color.cs
index 55ea746b2c9b55..dc7130b583bf60 100644
--- a/src/libraries/System.Drawing.Primitives/src/System/Drawing/Color.cs
+++ b/src/libraries/System.Drawing.Primitives/src/System/Drawing/Color.cs
@@ -249,6 +249,10 @@ namespace System.Drawing
 
         public static Color Purple => new Color(KnownColor.Purple);
 
+        /// <summary>
+        /// Gets a system-defined color that has an ARGB value of <c>#663399</c>.
+        /// </summary>
+        /// <value>A system-defined color.</value>
         public static Color RebeccaPurple => new Color(KnownColor.RebeccaPurple);
 
         public static Color Red => new Color(KnownColor.Red);