Fix color in validation exception message. Delete IgnoreAttribute.

Author: rstarkov

Src/Attributes.cs

@@ -31,14 +31,6 @@ public sealed class IsMandatoryAttribute() : Attribute
 {
 }
 
-/// <summary>Specifies that the command-line parser should ignore a field.</summary>
-[AttributeUsage(AttributeTargets.Field, Inherited = false, AllowMultiple = false)]
-public sealed class IgnoreAttribute : Attribute
-{
-    /// <summary>Constructor.</summary>
-    public IgnoreAttribute() { }
-}
-
 /// <summary>
 ///     Specifies that a field of an enum type should be interpreted as multiple possible options, each specified by an <see
 ///     cref="OptionAttribute"/> on the enum values in the enum type.</summary>

Src/CommandLineParser.cs

@@ -505,7 +505,7 @@ private static object parseCommandLine(string[] args, Type type, int i, Func<Con
         }
         catch (CommandLineValidationException exc) when (exc.GenerateHelpFunc == null)
         {
-            throw new CommandLineValidationException(exc.Message, getHelpGenerator(type, helpProcessor));
+            throw new CommandLineValidationException(exc.ColoredMessage, getHelpGenerator(type, helpProcessor));
         }
 
         return ret;