"Poor color vision is a reduced ability to distinguish between certain colors. Although many people use the term "colorblind" to refer to the reduced ability to discriminate between colors, true colorblindness is a total lack of color vision, which is rare.
Poor color vision is usually inherited. Men are more likely to be born with poor color vision. Most people with poor color vision can't distinguish between certain shades of red and green. Less commonly, people with poor color vision can't distinguish between shades of blue and yellow.
Certain eye diseases and some medications also can cause poor color vision." 
Types of Color Blindness - Learn more at http://www.color-blindness.com/
Coblis — Color Blindness Simulator
Protanopic (green) and deuteranopic (red) luminosity functions. For comparison, the standard photopic curve is shown in yellow. Color blindness changes the sensitivity of the eye as a function of wavelength. For people with protanopia, the peak of the eye's response is shifted toward the short-wave part of the spectrum (approximately 540 nm), while for people suffering deuteranopia, there is a slight shift in the peak of the spectrum, to about 560 nm. People with protanopia have essentially no sensitivity to light of wavelengths more than 670 nm.
Most mammals other than primates have the same luminosity function as people with protanopia. This makes it possible to study the nocturnal life of animals by illuminating the scene with long-wavelength red light that they can't see.
For older people with normal color vision, the crystalline lens may become slightly yellow due to cataracts, which moves the maximum of sensitivity to the red part of the spectrum and narrows the range of perceived wavelengths. 
Eyeborg - Colors as Sound
The Eyeborg is a device developed by Adam Montandan that incorporates the auditory and visual spectra. It makes it possible for people with color-blindness to hear colors. This device was inspired by naturally occurring synesthesia.
"The project I have created exists in outside the traditional domain of computer culture of physical installation. I have created a new sensation, a cyborgian extension of the human perception system residing in the brain of on student. Neil Harbisson." 
"Not many people go for a walk in the supermarket for fun, but I
do. I have an electronic eye that converts light into sound to
enable me to “hear” colour - so the cleaning product aisle is
very exciting. The rows of rainbow - coloured bottles sound like a symphony to me." Neil Harbisson 
Neil Harbisson, who has Achromatopsia and sees in black and white, is shown below testing the color to sound translation device, listening to color.
How does the eyeborg work?
Colour is basically hue, saturation, and light. Right now, I can see light in shades of grey, but I can't see its saturation or hue. The eyeborg detects the light's hue, and converts it into a sound frequency so it can easily convert the wavelength of light into a sound frequency. It also translates the saturation of the colour into volume, so if it's a vivid red I will hear it more loudly . 
TED TALK -I listen to color with Neil Harbission - http://www.ted.com/talks/neil_harbisson_i_listen_to_color
Excellent site for more information on color blindness.