class_docstr: RGB colors container
  
  Provides a quick color access.
  
  >>> from colour import HEX
  
  >>> HEX.WHITE
  '#fff'
  >>> HEX.BLUE
  '#00f'
  
  >>> HEX.DONOTEXISTS  # doctest: +ELLIPSIS
  Traceback (most recent call last):
  ...
  AttributeError: ... has no attribute 'DONOTEXISTS'
code: def __getattr__(self, value):
      return rgb2hex(getattr(RGB, value))
  
imports: from __future__ import with_statement, print_function
  import hashlib
  import re
  import sys
label_desc: Use image node_id 1 for calling the C_HEX obj's underlying member method code with example usage: obj.__getattr__(value) and returns: rgb2hex