# Color Perception

This section explains briefly how we perceive color.

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**Rods** and **Cones** are **photoreceptors** (or *sensors*) in the **retinas** of our eyes. The **Fovea** is a spot in the eye where these sensors are more densely located. The **blind spot** has no sensors and is the part of the eye where the **optic nerve** begins. The optic nerve transmits signals from the sensors to the brain.

**Rods** are used in low-light conditions and have low resolution.\
**Cones** are used in normal-light conditions and have high resolution.\
The **fovea** has a very high resolution.

There are **3 types** of cones, and each type is sensitive to different wavelengths:

* short wavelength (S)
* medium wavelength (M)
* long wavelength (L)

This, in turn, means that some cones are more sensitive around the wavelengths for red, some around those for blue and some for green.

![](https://612062878-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M5-0RG_uqhxyMNjpMUW%2F-M5-0SvQ45Rarxg8L2lA%2F-M5-0V67FrYv9EQay_50%2Fcones%20and%20wavelengths.PNG?generation=1586990823198119\&alt=media)

Therefore, every color can be expressed as a combination of 3 main channels.

This forms the basis for the **Trichromatic Theory** which states that we perceive color as a 3 channel system.

However, note that we **do not** perceive color in *amounts* of red, blue and green.

The **Opponent Process Theory** states that we perceive color as a 3 channel system, the 3 channels being:

1. Red-Green
2. Blue-Yellow
3. Black-White (luminance)

![](https://612062878-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M5-0RG_uqhxyMNjpMUW%2F-M5-0SvQ45Rarxg8L2lA%2F-M5-0V69FUkne6RA0ANN%2Fopponent%20process%20theory.PNG?generation=1586990822981108\&alt=media)
