using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"#([0-9A-Fa-f])([0-9A-Fa-f])((?=\2)\1|(?:\1\2){2})\b";
string input = @"#EEEEEE
#AAA
#EFE
#333333
#00006d
#123456
#ABABAB";
foreach (Match m in Regex.Matches(input, pattern))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx