# Matches an RGB Hex Color
\# # Number Sign followed by
(?>((?<Red>[0-9a-f]{2})   # EITHER: Two Hex Digits for Red
(?<Green>[0-9a-f]{2})     # Two Hex Digits for Green
(?<Blue>[0-9a-f]{2})      # Two Hex Digits for Blue
|(?<Red>[0-9a-f])         # OR: One Hex Digit for Red
(?<Green>[0-9a-f])        # One Hex Digit for Green
(?<Blue>[0-9a-f])         # One Hex Digit for Blue
))