Poinsettia length. The colored bracts—which are most often flaming red but can be orange, pale green, cream, pink, white, or marbled—are often mistaken for flower petals because of their groupings and colors, but are actually leaves. The colors of the bracts are created through photoperiodism, meaning that they require darkness (12 hours at a time for at least five days in a row) to change color. At the same time, the plants require abundant light during the day for the brightest color. The flowers of the poinsettia are unassuming and do not attract pollinators. They are grouped within small yellow structures
Color photography may be very inaccurate or completely arbitrary. The foundation of virtually all practical color processes, the three-color method was first suggested in an 1855 paper by Scottish physicist James Clerk Maxwell, with the first color photograph produced by Thomas Sutton for a Maxwell lecture in 1861. Color photography has been the dominant form of photography since the 1970s, with monochrome photography mostly relegated to niche markets such as art photography. Colour photography was attempted beginning in the 1840s. Early experiments were directed at finding a "chameleon substance" which would assume the colour of the light falling on it. Some encouraging