diff --git a/Pechkin/GlobalSettings.cs b/Pechkin/GlobalSettings.cs
index 292f6c1..4aec0ed 100644
--- a/Pechkin/GlobalSettings.cs
+++ b/Pechkin/GlobalSettings.cs
@@ -41,10 +41,18 @@ public enum PaperOrientation
         [WkhtmltopdfSetting("collate")]
         public bool? Collate { get; set; }
 
+        [WkhtmltopdfSetting("colorMode")]
+        internal string StringColorMode
+        {
+            get
+            {
+                return this.ColorMode == DocumentColorMode.Color ? "grayscale" : "color";
+            }
+        }
+
         /// <summary>
         /// Whether to print in color or grayscale. (Default: color)
         /// </summary>
-        [WkhtmltopdfSetting("colorMode")]
         public DocumentColorMode ColorMode { get; set; }
 
         /// <summary>
diff --git a/Pechkin/SettingApplicator.cs b/Pechkin/SettingApplicator.cs
index 60f24d1..6200ebc 100644
--- a/Pechkin/SettingApplicator.cs
+++ b/Pechkin/SettingApplicator.cs
@@ -47,13 +47,13 @@ public static void ApplySettings(IntPtr config, object settings, bool global = f
 
         private static string GetStringValue(PropertyInfo property, object value)
         {
-            var u = Nullable.GetUnderlyingType(property.PropertyType);
+            var type = property.PropertyType;
 
-            if (property.PropertyType == typeof(double?))
+            if (type == typeof(double?) || type == typeof(double))
             {
                 return ((double?)value).Value.ToString("0.##", CultureInfo.InvariantCulture);
             }
-            else if (property.PropertyType == typeof(bool?))
+            else if (type == typeof(bool?) || type == typeof(bool))
             {
                 return ((bool?)value).Value ? "true" : "false";
             }