Additive. Subtractive. Wavelengths. And the amazing things colors do for food.


natural colors of food1-Minute NomNom

Colors! We cannot taste them, but they are an important part of the food experience.

They can protect our food and drinks (e.g. colored wine bottles). They tell us if our food is ready (e.g. the golden brown from the Maillard reaction). They are also used to enhance the aesthetic of a dish (e.g. garnishing, toppings, or even something as simple as blanching vegetables).

The science of colors itself has two interesting phenomena: additive colors and subtractive colors.

Additive color model (and light)

Red, green, blue spot lights mixing shows additive colors model

The additive model can be thought of as what happens when we shine light rays of different colors sequentially in a dark room. Initially the room is black. When we flash a light ray e.g. red, we get a red beam of light. When we add (hence the term “additive”) another light ray e.g. blue, and the two rays mix, we get magenta. When we add a third light ray e.g. green, into the mix, we get white.

For additive colors, the three primary colors are red, green and blue (RGB). These three colors can be used to create any color using light. This is what happens with sunlight, torch lights, and computer monitors (which are made up of light-emitting diodes emitting different colors).

Subtractive color model (and paints, pigments and inks)subtractive colors model

The subtractive model can be thought of as what happens when the white light described above falls on an object. Each of the different colors in white light have different wavelengths. The object will absorb some of these (hence the term “subtractive”) and reflect the rest. A red apple has thus absorbed the green and blue in white light, reflecting the red; similarly the chlorophyll in green vegetables has absorbed most of the wavelengths of blue and red, and reflected the green.

For subtractive colors, the three primary colors are cyan, magenta and yellow. We associate these with primary colors in paints and pigments, but as kids we normally refer to them as red, blue and yellow. These can be used to create any color using paints and pigments.

subtractive colors - pigments and inks such as printer catridges

This is precisely what we see in color printers: The ink cartridges come in magenta, cyan and yellow (CMYK, where the K is for black ink).

It’s all connected!

Amazingly, additive colors and subtractive colors are closely intertwined. The former are the result of light rays and these light rays fall on objects (sunlight falling on a red tomato), but the colors we see are the result of the latter (the red tomato reflects the wavelengths of red and absorbs the rest).

The reflected color(s) travel to our eyes as light rays (i.e. additive), which then activate the respective cones in our eyes’ retina.

comparison of additive and subtractive color models

And here’s a fun fact: Have you noticed from the color venn diagrams above that where the additive colors overlap, they form subtractive colors (e.g. red + green = yellow)? And where the subtractive colors mix, they form additive colors (e.g. cyan + yellow = green)?


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Like this? Make me additive to your life by liking me to discover more! All you need is a minute a day to explore the world’s marvels through the phenomenon of food!


photos: in order – depositphotos/a_lisa; icefrontBigAlBaloo; Furianborojoint


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