Warn about overriding operator== but not hashCode.

dart/sdk/lib/_internal/compiler/implementation/colors.dart

Index: dart/sdk/lib/_internal/compiler/implementation/colors.dart
diff --git a/dart/sdk/lib/_internal/compiler/implementation/colors.dart b/dart/sdk/lib/_internal/compiler/implementation/colors.dart
index 42b3e7fde8497c0aa3c09b816b7575caf3a5b4e9..0c100854ea02911884664169832ead458b290bff 100644
--- a/dart/sdk/lib/_internal/compiler/implementation/colors.dart
+++ b/dart/sdk/lib/_internal/compiler/implementation/colors.dart
@@ -4,12 +4,26 @@
 
 library colors;
 
-const String GREEN_COLOR = '\u001b[32m';
+// See http://en.wikipedia.org/wiki/ANSI_escape_code#CSI_codes
+const String RESET = '\u001b[0m';
+
+// See http://en.wikipedia.org/wiki/ANSI_escape_code#Colors
+const String BLACK_COLOR = '\u001b[30m';
 const String RED_COLOR = '\u001b[31m';
+const String GREEN_COLOR = '\u001b[32m';
+const String YELLOW_COLOR = '\u001b[33m';
+const String BLUE_COLOR = '\u001b[34m';
 const String MAGENTA_COLOR = '\u001b[35m';
-const String NO_COLOR = '\u001b[0m';
+const String CYAN_COLOR = '\u001b[36m';
+const String WHITE_COLOR = '\u001b[37m';
 
-String wrap(String string, String color) => "${color}$string${NO_COLOR}";
-String green(String string) => wrap(string, GREEN_COLOR);
+String wrap(String string, String color) => "${color}$string${RESET}";
+
+String black(String string) => wrap(string, BLACK_COLOR);
 String red(String string) => wrap(string, RED_COLOR);
+String green(String string) => wrap(string, GREEN_COLOR);
+String yellow(String string) => wrap(string, YELLOW_COLOR);
+String blue(String string) => wrap(string, BLUE_COLOR);
 String magenta(String string) => wrap(string, MAGENTA_COLOR);
+String cyan(String string) => wrap(string, CYAN_COLOR);
+String white(String string) => wrap(string, WHITE_COLOR);