Oriental Lilies

I have Oriental Lilies which have been in a tub for a few years now but this year, unless I am beginning to turn colour blind in my old age, they have changed colour from  a deep red/pink into a definite rich purple.  Somebody please put my mind at rest and tell me this can happen!!   Thanks 

Well I just found this on a website called The Lily Pad "Do lilies "revert" back to ancestral types?

No, this is not the case. Oriental lilies cannot change to Asiatic types, nor can lilies change their basic color. Mutations are remotely possible, but extremely rare. In certain instances, color intensity can be affected by environmental variables, but this is probably a one season fluke."

Alternatively were you wearing your sun glasses at the time? If I fancy a change of colour in the garden I pop on my sunnies. Much cheaper than buying new plants! 

Thanks to both Lorelei and Quercus-ruber for responding to my question.  I did have a good laugh at the sunglasses statement, but I dont think so.  I must admit I'm not dissapointed because its a beautiful colour.  Lets see what next year brings.