Exploring the Impossible Colors: Why Certain Hues Can't be Made from Primary Pigments

Why are certain colors impossible to create using just the primary pigments? This question has puzzled creators and artists for years. In this article, we peel back the layers and explore the limitations of using primary colors to replicate vivid, pure hues.

Understanding the Primary Pigments

When it comes to creating colors through pigments, the traditional primaries often are not sufficient to produce pure hues. Red, Yellow, and Blue (RYB) are commonly taught as the primary colors in school, but they are not accurate.

Instead, the modern primary pigments are typically Cyan (C), Magenta (M), and Yellow (Y). These three pigments can mix a wide range of hues reasonably well. However, for pure hues, you might need to augment your palette. For instance, the addition of a light red (such as PY6), an ultramarine blue (Pigment Blue 29, PB29), and specific yellows (like Lemon Yellow, PV35, and Golden Yellow, PY153) can help achieve pure greens, oranges, and purples.

Creating Pure Hues with Primary Pigments

Green: A pure green can be created by mixing a cyan (such as Veridian Green PG18 or Phthalocyanine Blue PB15) with a yellow (Lemon Yellow, PV35).

Orange: A bright orange can be achieved by mixing a light red (such as Permanent Alizarin Crimson PY38) with a golden yellow (PY153).

Purple: For pure purples and violets, mix a magenta (Permanent Rose PR122) with an ultramarine blue (PB29).

Additive Primaries: A Different Perspective

While subtractive primary colors (CMY) refer to pigmentation, additive primaries (Red, Green, Blue, RGB) are used when dealing with colored light. Though the principles are similar, the color space for light is different from that of pigments. This aspect is crucial for electronic displays like TV screens and computer monitors.

Understanding Color Gamut

A color gamut represents the range of colors that can be reproduced or displayed using a specific set of colors. When you plot the colors on a 2D chart, you can see the boundaries of the color gamut for that set of primary colors. However, no set of primary colors can cover the entire range of visible colors.

Take, for example, two sets of primary colors: CMY and RGB. Charts showing these color gamuts reveal that they are far from covering the full color space. The shape of the color space is determined by the way our visual system perceives colors. It is impossible to create a set of primary colors that can reproduce all visible colors practicality. The space is too vast, and the number of primary colors is insufficient.

Practical Solutions and Artistry

While it is impossible to perfectly replicate all colors using a limited set of primary colors, there are always practical solutions. Art stores, for instance, offer a wide range of pigments that can help achieve nearly any color. When mixing colors, experimentation and understanding the limitations of each pigment are crucial. Artists and creators often develop their own palettes that best suit their needs.

The key takeaway is that while certain colors may be ‘impossible’ to create using just primary pigments, this doesn’t diminish the beauty and complexity of color creation. The art of mixing colors is a process of understanding, experimenting, and creating. And if you can’t see it, it isn’t a color.

Conclusion: The primary colors and color gamut limitations point to the fascinating challenges and complexities in color mixing. While it is impossible to replicate all colors using just primary pigments, the world of art and design offers numerous solutions and creative possibilities.