fix colors calculate error

com.unity.uiwidgets/Runtime/painting/colors.cs

             if (max == 0.0f || delta == 0.0f) {
                 hue = 0.0f;
             }
-            else if (max == red) {
+            else if (Math.Abs(max - red) < foundation_.precisionErrorTolerance) {
-            else if (max == green) {
+            else if (Math.Abs(max - green) < foundation_.precisionErrorTolerance) {
-            else if (max == blue) {
+            else if (Math.Abs(max - blue) < foundation_.precisionErrorTolerance) {
                 hue = 60.0f * (((red - green) / delta) + 4);
             }
 
         }
         
         public static HSVColor fromColor(Color color) {
-            float red = color.red / 0xFF;
-            float green = color.green / 0xFF;
-            float blue = color.blue / 0xFF;
+            float red = (float)color.red / 0xFF;
+            float green = (float)color.green / 0xFF;
+            float blue = (float)color.blue / 0xFF;
-            float alpha = color.alpha / 0xFF;
+            float alpha = (float)color.alpha / 0xFF;
             float hue = painting_._getHue(red, green, blue, max, delta);
             float saturation = max == 0.0f ? 0.0f : delta / max;
             
         }
 
         public static HSLColor fromColor(Color color) {
-            float red = color.red / 0xFF;
-            float green = color.green / 0xFF;
-            float blue = color.blue / 0xFF;
+            float red = (float)color.red / 0xFF;
+            float green = (float)color.green / 0xFF;
+            float blue = (float)color.blue / 0xFF;
-            float alpha = color.alpha / 0xFF;
+            float alpha = (float)color.alpha / 0xFF;
-            float saturation = lightness == 1.0f
+            float saturation = Math.Abs(lightness - 1.0f) < foundation_.precisionErrorTolerance
                 ? 0.0f
                 : ((delta / (1.0f - Mathf.Abs(2.0f * lightness - 1.0f))).clamp(0.0f, 1.0f));
             return HSLColor.fromAHSL(alpha, hue, saturation, lightness);