Color Spectrum

The visible color spectrum, with wavelengths indicated in nanometers.From https://commons.wikimedia.org/wiki/File:Spectrum441pxWithnm.png

Retinal Layers

Schematic of layers in the retina. The back of the retina is at the top of the diagram. Adapted from work made available by Peter Hartmann and Marc Gabriel Schmid.https://commons.wikimedia.org/wiki/File:Retina.jpg

Photoreceptor Sensitivity

The sensitivity (absorbance) of the different types of photoreceptors as a function of wavelength. Each curve is normalized to a maximum of 100. Short (S), medium (M) and long (L) wavelength cones are shown in solid blue, green and red, respectively. Rod absorbance is shown as the dashed black line.From https://commons.wikimedia.org/wiki/File:Cone-response.svg

Rose Garden

A scene from a rose garden as viewed by someone with working M and L cones (top) compared to the same scene viewed by someone with only one working type of cone. With only one cone, only brightness is recorded; there is no color information.

Color Mixing with iPhones

Three iPhones displaying three colors, on the floor facing up.

The same three iPhones stood up on edge, leaning against each other in a triangle. Red, green and blue light from the phones combine to form white light.

Magnified Soap Film

Soap film as displayed on an iPad. (top) Full picture. (middle) Close up. This image starts to show the individual pixels in the screen. (bottom) Microscope view at 40X. The individual pixels are shown as blue-red-green triplets of LCDs.

Color Vision Test

A plate from the Ishihara color perception test. The number "74" should be clearly visible to viewers with normal color vision. Viewers with one missing or altered cone type may read it as "21".From https://commons.wikimedia.org/wiki/File:Ishihara_9.png