Computers, TVs and phones use the additive RGB colour model to represent colour. It’s called additive because it works by adding different coloured lights together to create new colours.
Although all the displays on these devices use the RGB colour model, they can still be used to explore the effects of subtractive colour models such as CMY or RYB.
Subtractive colour models used in printing work by subtracting colours from white light to produce different hues.
In the CMY model, the primary colours are cyan, magenta, and yellow, while in the RYB model, the primary colours are red, yellow, and blue.
By using a computer, TV, or phone to explore subtractive colour models, it’s possible to visualize how colours are created by subtracting different wavelengths of light.
The ability to explore subtractive colour models using computers, TVs, and phones can be useful for designers, artists, and anyone working in the printing industry, as it allows for a better understanding of how colours are created and manipulated using different colour models and media.
Regardless of whether additive or subtractive colour is to be explored the easiest way to identify the relationship between colours is by using a colour picker.
A colour picker is a visual tool that allows the user to select a colour from a colour spectrum or a colour model such as RGB, HSL, or CMYK.
Some colour pickers include numeric input fields for entering exact colour values, or a colour palette that includes predefined colours.
Colour pickers may show colour relationships in the form of a grid, wheel or in-line with one another.
The alternative to colour pickers is to calculate the relationship between colour values mathematically but can be a time-consuming process.
Mixing CMY colours on screen
The primary colours in the CMY colour model are:
Cyan
Magenta
Yellow
A secondary colour is produced by mixing two primary colours of equal intensity:
Magenta + Yellow = Red
Yellow + Cyan = Green
Cyan + Magenta = blue
Mixing secondary colours produces darker versions of their common primary colour:
Green + Blue = dark cyan or teal
Blue + Red = dark magenta or purple
Red + Green = dark yellow or olive.
Each secondary colour is the complement of one primary colour:
Red complements cyan
Green complements magenta
Blue complements yellow
When a primary and its complementary secondary colour are mixed together, the resulting colour is the very dark version of the mixed primary colour:
Cyan + Red = a very dark cyan or dark teal
Magenta + Green = a very dark magenta or dark purple
Yellow + Blue = a very dark yellow or dark olive
The exact colour depends on the specific tints of shades of the colours being used and the proportions in which they are mixed.
When all the primary colours are mixed in equal intensities, the result is a dark grey or brown colour, but not true black.
True black is achieved by using black ink (K) in addition to the CMY colours, creating the CMYK colour model commonly used in printing.
Mixing RYB colours on screen
The primary colours in the RYB colour model are:
Red
Yellow
Blue
A secondary colour is produced by mixing two primary colours of equal intensity:
Red + Yellow = Orange
Yellow + Blue = Green
Blue + Red = Purple
Mixing secondary colours produces darker versions of their common primary colour:
Green + Purple = Dark Blue
Purple + Orange = Dark Red
Orange + Green = Dark Yellow
Each secondary colour is the complement of one primary colour:
Orange complements blue
Green complements red
Purple complements yellow
When a primary and its complementary secondary colour are mixed together, the resulting colour is the very dark version of the mixed primary colour:
Blue + Orange = Dark brown
Red + Green = Dark olive
Yellow + Purple = Brown
The exact colour depends on the specific tints of shades of the colours being used and the proportions in which they are mixed.
When all the primary colours are mixed in equal intensities, the result is a dark grey or brown colour, but not true black.
True black can be achieved by adding black paint or ink.