Fixes transparency issue

-  This resolves the issue #289

Author: paulushub

Source/SharpVectorCss/Css/CssPrimitiveColorValue.cs

@@ -7,10 +7,15 @@ public sealed class CssPrimitiveColorValue : CssPrimitiveValue
         public CssPrimitiveColorValue(int color, bool readOnly)
             : base(color.ToString(CssNumber.Format), readOnly)
         {
-            if (color < 0)
+            if (color <= 0)
             {
                 SetFloatValue(0);
             }
+            else if (color > 0 && color <= 1)
+            {
+                color = (int)(255 * color);
+                SetFloatValue(color);
+            }
             else if (color > 255)
             {
                 SetFloatValue(255);
@@ -49,10 +54,14 @@ protected override void OnSetCssText(string cssText)
 
             }
             var color = double.Parse(cssText, CssNumber.Format);
-            if (color < 0)
+            if (color <= 0)
             {
                 color = 0;
             }
+            else if (color > 0 && color <= 1)
+            {
+                color = (int)(255 * color);
+            }
             else if (color > 255)
             {
                 color = 255;