In the realm of color theory and mathematics, the concept of e-number colors is an intriguing intersection that has captivated both artists and scientists. This unique system, developed by artist and mathematician Mark J. Stock, assigns a numerical value to colors based on their hue, saturation, and brightness, creating a fascinating bridge between the visual and numerical worlds. Let's delve into the fascinating world of e-number colors.
Understanding the E-Number Color System
The e-number color system is a logarithmic scale that assigns a unique number to each color based on its position in a three-dimensional color space. This space is defined by the three primary colors (red, green, and blue), with brightness acting as the fourth dimension. The 'e' in e-number colors refers to the base of the natural logarithm, which is approximately equal to 2.71828. This choice is not arbitrary; it's deeply rooted in the mathematical properties of the system.
How E-Number Colors Are Calculated
Each color in the e-number system is represented by a number between 0 and 100,000. This number is calculated using the following formula:

| Hue (H) | Saturation (S) | Brightness (B) |
|---|---|---|
| H / 360 | S / 100 | B / 100 |
The resulting values are then multiplied by 100,000 and rounded to the nearest whole number to obtain the e-number. For example, pure red (hue 0, saturation 100, brightness 100) would have an e-number of approximately 31,622.
Exploring the E-Number Color Space
The e-number color space is not linear, but rather logarithmic, meaning that each increment in the e-number represents a doubling of the color's intensity. This property creates a rich and complex color space, with a vast array of colors available for exploration. Here are a few notable e-numbers and the colors they represent:
- 10,000: A soft, desaturated yellow-green
- 20,000: A vibrant, saturated blue
- 30,000: A deep, rich red
- 40,000: A dark, nearly black purple
The Aesthetic and Practical Applications of E-Number Colors
The e-number color system has a wide range of applications, from art and design to science and technology. In the realm of art, e-number colors offer artists a new way to think about and represent color. By assigning a numerical value to each color, artists can create complex, mathematically-based color palettes and explore the relationships between different colors in a systematic way.

In the field of science and technology, e-number colors have been used to create color scales for scientific visualizations, such as those used in medical imaging or climate modeling. The logarithmic nature of the e-number system makes it well-suited to representing data that spans a wide range of values, from very small to very large.
E-Number Colors in Practice
Several artists and designers have adopted the e-number color system and used it to create striking and innovative work. For example, artist and designer Daniel Shiffman has used e-number colors to create a series of generative artworks that explore the mathematical properties of the color space. Similarly, designer and educator Elliot Earls has used e-number colors in his teaching and design practice, creating a range of color palettes and visualizations that demonstrate the system's aesthetic and practical potential.
Moreover, the e-number color system has inspired a range of tools and resources for artists and designers. These include color pickers, palettes, and generators that allow users to explore the e-number color space and create their own e-number-based designs. Some popular examples include the e-number color picker created by designer and developer Robby Leonardi, and the e-number color palette generator created by artist and designer Daniel Shiffman.

In conclusion, the e-number color system is a fascinating and versatile tool for artists, designers, and scientists. By assigning a numerical value to each color, the e-number system offers a new way to think about and represent color, with a wide range of aesthetic and practical applications. Whether you're an artist looking to explore new color palettes, a designer seeking to create visually striking data visualizations, or a scientist in need of a robust color scale, the e-number color system has something to offer you.






















