Could be a nute lock out, happened to my plants
Sorry Guys, I should have been more accurate in my post. The plants stems and stocks have been purple for almost 2 months and the plant has doubled in size, but the 3 week old buds are now starting to show purple hairs. I have 4 sativa's only 1 has purple bud's and 6 indica's and only one showing purple. nutes the same for all, so I don't think nute block but I could be wrong.
That pic was taken before I watered them thats why the druppy leaves. I have to water 2 times a day, morning and evening the way my buckets drain