Simplify internal CSS-version handling for colors

Internally the code was maintaining a list of “CSS4” colors and a list of “CSS3”
colors, but the only difference between the two was the color `rebeccapurple`.

So this change adds `rebeccapurple` to the list of “CSS3” colors and changes the
rest of the code to use that wherever it was previously using the “CSS4” list.

That old code was the only place where a “CSS4” distinction was used for any
feature being checked. So this change makes the color-checking version behavior
consistent with the rest of the code, where the “CSS3” label now just means in
practice “the latest relevant spec for whatever feature is being checked”.

Author: sideshowbarker

org/w3c/css/values/CssColor.java

@@ -307,6 +307,7 @@ protected void setIdentColor(String s, ApplContext ac)
 				break;
 			case CSS3:
 			case CSS_2015:
+			case CSS:
 				// test RGB colors, RGBA colors (transparent), deprecated system colors
 				rgb = CssColorCSS3.getRGB(lower_s);
 				if (rgb != null) {
@@ -325,25 +326,6 @@ protected void setIdentColor(String s, ApplContext ac)
 				}
 				// inherit or current color will be handled in the property def
 				throw new InvalidParamException("value", s, "color", ac);
-			case CSS:
-				// test RGB colors, RGBA colors (transparent), deprecated system colors
-				rgb = CssColorCSS4.getRGB(lower_s);
-				if (rgb != null) {
-					color = lower_s;
-					break;
-				}
-				rgba = CssColorCSS4.getRGBA(lower_s);
-				if (rgba != null) {
-					color = lower_s;
-					break;
-				}
-				color = CssColorCSS4.getSystem(lower_s);
-				if (color != null) {
-					ac.getFrame().addWarning("deprecated", s);
-					break;
-				}
-				// inherit or current color will be handled in the property def
-				throw new InvalidParamException("value", s, "color", ac);
 			default:
 				throw new InvalidParamException("value", s, "color", ac);
 		}

org/w3c/css/values/CssColorCSS3.java

@@ -7,7 +7,7 @@
 import java.util.HashMap;
 
 /**
- * @spec http://www.w3.org/TR/2011/REC-css3-color-20110607/
+ * @spec https://www.w3.org/TR/2016/WD-css-color-4-20160705/
  */
 public class CssColorCSS3 {
     protected static final HashMap<String, RGB> definedRGBColorsCSS3;
@@ -34,7 +34,7 @@ public static String getSystem(String ident) {
 
     static {
         trans = new RGBA(0,0,0,0.f);
-        // http://www.w3.org/TR/2011/REC-css3-color-20110607/#svg-color
+        // https://www.w3.org/TR/2016/WD-css-color-4-20160705/#named-colors
         definedRGBColorsCSS3 = new HashMap<String, RGB>();
 
         definedRGBColorsCSS3.put("aliceblue", new RGB(240, 248, 255));
@@ -156,6 +156,7 @@ public static String getSystem(String ident) {
         definedRGBColorsCSS3.put("plum", new RGB(221, 160, 221));
         definedRGBColorsCSS3.put("powderblue", new RGB(176, 224, 230));
         definedRGBColorsCSS3.put("purple", new RGB(128, 0, 128));
+        definedRGBColorsCSS3.put("rebeccapurple", new RGB(102, 51, 153));
         definedRGBColorsCSS3.put("red", new RGB(255, 0, 0));
         definedRGBColorsCSS3.put("rosybrown", new RGB(188, 143, 143));
         definedRGBColorsCSS3.put("royalblue", new RGB(65, 105, 225));