London-based studio Bompas & Parr has created two kinds of "chameleon bloom" for Valentine's Day that change colour when exposed to certain temperatures (+ slideshow).

Demonstration of the effect of thermochronic ink on a rose

Described by Bompas & Parr as "the world's first colour changing flowers", each of the blooms is hand painted with thermochromic ink ? a substance that changes colour in response to fluctuations in temperature.
The studio is using two kinds of the ink to create different effects.

One set of flowers is treated with a liquid crystal dye that ? at 27 degrees Celsius ? changes from black to blue, passing through a number of other colours similar to those found on a beetle's shell. "As you touch the petals the iridescent blooms go from black, to russet to champagne bottle green and then finally to a cerulean blue," studio co-founder Sam Bompas told Dezeen. "These flowers are sensual and luxuries, a deluxe, techno-enhanced model of what others will gift on Valentine's day."

The second set is treated with a black thermochromic dye that transforms at 31 degrees Celsius.
These plants are then sprayed with a "perfumed crystal elixir" before being burned. The heat triggers an effect that makes the flower's original colour reappear.
"The idea came to me in a lurid dream - a symphony of psychedelic blossoms," said Bompas. "There?s been so little innovation in the realm of fl...