One Plant With Purple Buds.. What is This?

I have 7 female plants. I ordered the seeds from Nirvana and grew them up. Now they're in budding.

6 of the plants look the same. But they're all White Widow.

Why would one have purple buds? Why should it be different?

Anyway, should I clone it? Is it any good? Is it still White Widow like the rest?

it could be any of a bunch of reasons.
-a stray seed got mixed in the white widows at the breeders packaging facility.
-a rare pheno that may be worth keeping.
-just genetics that responded differently to your water and nutes
-etc.etc. you can guess all you want

when i harvest, i like to keep all my plants seperated and labeled in their own jars until i have a good cure and can test them. sometimes different plants in the same strain will taste different and the effect can be different. once i verify that they are the same or close i will put it in the same jar.

i also like to prune out the lower 1/3 of the branches before going to 12/12.
when i do that i will clone a couple off of each plant. place them into a veg. room until the first plants are done. then prune and take clones from the clones and place the first set of clones into flower. make sure to have all clones labeled so you know what mother it came from.
by now you should have sampled the first round and should be able to sort out the unwanted plants and concentrate on growing the ones you want.

is it really a bad thing to have purple buds?......i think not.