Corrected the ToShortString method of MagickColor for CMYK.

Author: dlemstra

src/Magick.NET/Colors/MagickColor.cs

@@ -461,7 +461,15 @@ public string ToShortString()
                 return ToString();
 
             if (IsCmyk)
-                return string.Format(CultureInfo.InvariantCulture, "cmyk({0},{1},{2},{3})", R, G, B, K);
+            {
+                var r = Quantum.ScaleToByte(R);
+                var g = Quantum.ScaleToByte(G);
+                var b = Quantum.ScaleToByte(B);
+                var k = Quantum.ScaleToByte(K);
+
+                return string.Format(CultureInfo.InvariantCulture, "cmyk({0},{1},{2},{3})", r, g, b, k);
+            }
+
 #if Q8
             return string.Format(CultureInfo.InvariantCulture, "#{0:X2}{1:X2}{2:X2}", R, G, B);
 #elif Q16 || Q16HDRI

tests/Magick.NET.Tests/Colors/MagickColorTests/TheToShortStringMethod.cs

@@ -40,7 +40,7 @@ public void ShouldIncludeTheAlphaChannelWhenNotFullyOpquery()
             public void ShouldReturnTheCorrectStringForCmykColor()
             {
                 var color = new MagickColor(0, Quantum.Max, 0, 0, Quantum.Max);
-                Assert.Equal("cmyk(0," + Quantum.Max + ",0,0)", color.ToShortString());
+                Assert.Equal("cmyk(0,255,0,0)", color.ToShortString());
             }
         }
     }