Strange S-50 lens hood variation for 50/1.4

[tonal1]

I have had this Canon lens hood for a long time, and can't figure out why it exists. It's the standard Canon S-50 for the 50/1.4, but it has a slightly purplish/champagne color to it, instead of the usual black. Anyone know about this? Is this just a production variation, or something else?

Thanks!

 

[John Shriver]

Perhaps it has been laundered, or run through a dishwasher? The latter can do a job on an anodized finish on aluminum.