Colors Bees See

What colors creatures see has long interested scientists, and aside from us, more is known about what colors bees see than any other living thing.  Like us, bees are trichromatic (have three photoreceptors within the eye).  Whereas we base our color combinations on red, blue, and green, bees base all their colors on UV, blue , and green.  Just as color blind people do not see red or green, and therefore experience the world of color differently, bees also perceive the world in colors entirely different from ours.  Bees do not see red and have a hard time distinguishing it from surrounding green leaf backgrounds.  Bees that frequent red flowers are either perceive them in color they can see, or the red flower is not being lost against a green background. Even though bees don't see red, they can see other reddish wavelengths such as orange and yellow.

The light spectrum bees see is from 600 - 300 nm. The colors bees see are blue-green, blue, violet, and ultraviolet, with research showing our purple followed by our violet then our blue as their favorites. Mixing ultraviolet wavelengths with the wavelengths of colors they can and can't see, gives bees a world of color different from our own.   If deprived of UV light, bees lose interest in foraging, and remain in the hive until forced out by severe food shortages.

Bees not only see flowers in different colors than we do, bees also see ultra-violet light patterns, invisible to us, at the center that are a different color than the rest of the flower.   From a bee's-eye-view, the UV colors and patterns in a flower's petals dramatically announce the flower's stash of nectar and pollen.  These UV patterns serve as a landing zone, guiding the bees to the nectar source. 

we see 
bees see
add in UV
red black uv purple
orange yellow/green*  
yellow yellow/green* uv purple
green green  
blue blue uv violet
violet blue uv blue
purple blue  
white blue green  
black black  


Understanding Color

To better understand what colors bees see, first we have to understand color.  Isaac Newton discovered in 1672 that light  could be split into many colors by a prism, and used this new concept to analyze light.   The colors produced by light passing through a prism are arranged in a precise spectrum from red through orange, yellow, green, blue, indigo and into violet. The order of colors is constant, and each color has a unique signature identifying its location in the spectrum.   That signature of color is the wavelength of light.

Light travels in the form of a wave. When we consider light as an electromagnetic wave, a color's spectral signature may be identified by noting its wavelength. We sense the waves as color,  with red being the longest wavelength and violet the shortest.  Visible light is the range of wavelengths within the electromagnetic spectrum that the eye responds to.   Waves exist above and below the visible spectrum that the human eye is not capable of responding to.  Radio, microwave, and infrared are longer waves below the red end of the spectrum, and ultraviolet (UV), x-rays, and gamma rays are shorter waves above the violet.  These cannot be seen by the human eye, and constitute the "invisible" spectrum.  While most people can not see UV light because the lens in our eyes absorbs UV; after cataract surgery, a condition called aphakia, "near" UV light (300 - 400 nm) can reach visual receptors.   It is perceived as a whiteish blue to  whiteish violet.  Paintings by Monet from before and after his cataract surgery.


No single wavelength exists for the color purple, it is the result of mixing the red and blue wavelengths.  Since purple cannot be represented by a single wavelength of light, light experts don't consider it a pure color.  Just as none exists for purple, no single wavelength exists for the color brown.  While purple can be created with a mixture of wavelengths of both red and blue, brown requires a more complex mixture of wavelengths from at least three regions of the sequence.  White is the presence of all color and black is the absence of all color. 

The light palette (the mixing of colored light) known as the additive primaries, consists of red, green, and blue (RGB), is so named because black is the base and light is "added" to eventually get to white, which is all of the colors together. Television along with computer and video displays are common examples of the use of additive primaries. The artist's palette( the mixing of light and pigments), known as the subtractive primaries, is red, yellow, and blue.   RYB is the historical set of subtractive primary colors, and is used in art and art education.  RYB cannot mix all other colors, so a second subtractive palette cyan, magenta, and yellow (CMYK) is used for printed publications.   These subtractive colors are also the secondary colors in light palette: cyan, magenta, and yellow.  Black is used in the subtractive model as well, because cyan, magenta, and yellow make more of a dark gray than pure black when they are combined.  In the subtractive coloring, light not absorbed by the surface (reflected back) is the color we see.

 

       additive primaries               subtractive primaries     subtractive primaries
       
TVs, video displays                               print media                                               art


            

*even the experts don't agree
as to what color the bee sees

http://www.naturfotograf.com/UV_flowers_list.html

     Photographs of flowers taken with uv filters
showing the landing patterns and flouresence. 
The color of these uv flowers is dependant on
the filter used by the photographer, and is not
the color perceived by the bee.