1def _IsColor(color):
2  """Try to determine if color is a hex color string.
3  Labels that look like hex colors will match too, unfortunately."""
4  if not isinstance(color, basestring):
5    return False
6  color = color.strip('#')
7  if len(color) != 3 and len(color) != 6:
8    return False
9  hex_letters = '0123456789abcdefABCDEF'
10  for letter in color:
11    if letter not in hex_letters:
12      return False
13  return True
14