Is this a Sun Halo?

Photo of a Canon 350 D Digital taken by Bernard Tenand from the terrace of the Café de Paris in St Malo intra-muros on June 11, 2011 at 1 p.m. There was a rainbow halo around the sun. It appears less in the photo. When presenting the pendulum on the sun it swings strongly, between the sun and the crown nothing and on the crown it vibrates again very strongly.

For my part, this is the first time that I have observed this particularity, with these colors around the sun and on the halo.

Notice to any interpretations?