no need to dead head as Rozanne is sterile. The colour is slightly variable depending on how bright the sun is

And how hot it is. My Rozanne is almost fluorescent in spring, a hard to describe shimmering blue/lavender, but has smaller, bluer flowers now when it's 100 F or above. As the flowers age they change color too, I love this plant.

My Rozanne flowers are purple.

I've noticed that when hardy geraniums are described as blue, it seems to be more on the purple side of the color.

Mine was more purple than blue in the middle of summer. Now, the ones in partial shade are bluer and larger than the ones in full sun. Go figure. I'll get a few more next spring.

Love this geranium.

Some of mine have turned indigo! Wow. Each blossom has grown almost twice as large as those that bloomed in the summer. I am impressed.