[C_P_A_L_] make Color a subclass of namedtuple
[C_P_A_L_] make Color a subclass of namedtuple

so that's comparable/hashable/immutable and can be used as key in a dict or set.

The fromXML instance method was dropped since it relied on the object being mutable.
A fromHex classmethod replaces it.

fonttools/fonttools,googlefonts/fonttools