The Blue Hour is that time between sunset and dark, when the sky turns a midnight blue. I’d never heard of it until I went on a tour with Daniel Georghita of http://www.covinnus.com/.
Just past sunset, the domes of Registan in Samarkand started to glow this magical blue color. I didn’t do anything in Photoshop!
If you want to visit Registan Square during the blue hour, go to www.uzbekjourneys.com .