I used to own a popular Henna body art business in Boulder, Colorado. Most of the designs requested were traditional Indian style, but I was often asked to do tribal, southwest art, Celtic and even copy things from photos, like the Titan Rocket shown in the photo grid below. The areas where you soo sparkly color are either glitter glue or glitter sprinkled onto wet henna. 

My henna process involved a paste recipe that had to be made 24 hours prior to use and aftercare instructions that might include wrapping the hennaed areas overnight to obtain the darkest, longest-lasting color. It is completely painless and uses 100% safe, natural ingredients with no permanent dyes or needles like regular tattoos.

Henna designs typically last 3-4 weeks, if placed in a thick skin area like hands and feet. Facial henna would only last a few days due to the thinness of skin. 

The final color of henna designs, after the removal of the paste, should always be red, orange or brown. Where you see black in the above photos is the dried henna paste itself.

Added more photos above, where you can see the shiny, dark green color of wet henna paste, plus a couple of finished color designs. There are also a couple of hands in here that are a very special ode to Jim Henson, the creator behind The Dark Crystal.