fix Media.Color

Author: halgab

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/Color.cs

@@ -265,8 +265,8 @@ string IFormattable.ToString(string format, IFormatProvider provider)
         }
 
         /// <summary>
-        /// Creates a string representation of this object based on the format string 
-        /// and IFormatProvider passed in.  
+        /// Creates a string representation of this object based on the format string
+        /// and IFormatProvider passed in.
         /// If the provider is null, the CurrentCulture is used.
         /// See the documentation for IFormattable for more information.
         /// </summary>
@@ -303,10 +303,14 @@ internal string ConvertToString(string format, IFormatProvider provider)
                 String uriString = safeUnescapedUri.GetComponents(UriComponents.SerializationInfoString, UriFormat.UriEscaped);
 
                 var sb = new StringBuilder();
-                sb.Append(provider, $"{Parsers.s_ContextColor}{uriString}{scRgbColor.a:R}");
+                sb.Append(provider, $"{Parsers.s_ContextColor}{uriString} {scRgbColor.a:R}{separator}");
                 for (int i= 0; i< nativeColorValue.Length; ++i )
                 {
-                    sb.Append(provider, $"{separator}{nativeColorValue[i]:R}");
+                    sb.Append(provider, $"{nativeColorValue[i]:R}");
+                    if (i< nativeColorValue.GetLength(0)-1 )
+                    {
+                        sb.Append(provider, $"{separator}");
+                    }
                 }
                 return sb.ToString();
             }
@@ -413,7 +417,7 @@ public float[] GetNativeColorValues()
             {
                 Color c1 = new Color();
                 c1.context = color1.context;
-                
+
                 #pragma warning suppress 6506 // c1.context is obviously not null - both color1.context AND color2.context are not null
                 c1.nativeColorValue = new float[c1.context.NumChannels];
                 for (int i = 0; i < c1.nativeColorValue.GetLength(0); i++)