I used to buy blue roses when I was in Paris. Not my favourite color for a rose (I much preferred bright red or a mix of yellow and orange), but also quite enjoyed the blue ones, which as far as I know where made out of white ones in blue-inked water. Apparently some Japanese folks managed engineer true blue roses. I need to put my hands on one of those... [article] World's first blue roses after 20 years of research.

This said, I would say they are purple, not blue....