How Did Synthetic Dyes Change the World? Let’s Explore Color Expression with AI Illustrations!

Introduction

Hello, I’m Easygoing!

In this post, I’d like to dive into the fascinating world of color expression in AI-generated illustrations.

Exploring Blue, Purple, and Red

Today, we’ll focus on three captivating colors:

• Blue: Indigo
• Purple: Tyrian Purple, Royal Purple
• Red: Alizarin

These colors are known for their vibrant and rich tones, historically used as natural dyes for centuries.

Indigo Blue: A Familiar Dye Across Cultures

Indigo is perhaps the dye most deeply intertwined with human history.

Its name comes from the Latin word indicum ("from India"), hinting at its ancient trade along the Silk Road, where Indian blue dye reached the Mediterranean.

Natural indigo is produced through a complex process of fermentation and oxidation of plant leaves containing the dye’s pigment.

Indigo dyeing was practiced worldwide, and in Japan, ai (indigo) was widely cultivated in Awa Province (modern-day Tokushima), used for clothing and as a pigment in traditional paintings.

Indigo’s Molecular Magic: Capturing Light

Indigo’s molecular structure consists of two cyclic indican molecules bonded together.

At its core is a benzene ring, resembling a hexagonal turtle shell, with a conjugated system of alternating single and double bonds.

This structure absorbs specific wavelengths of light, allowing indigo to soak up red and green light from sunlight, resulting in its deep blue hue.

Purple Dye: Sourced from Seashells

A close cousin to indigo is Tyrian Purple (Royal Purple).

Tyrian purple is created when bromine (Br) is added to the indigo molecule, altering the wavelengths of light it absorbs.

Its name derives from Tyre (modern-day Sour, Lebanon), a city in the ancient Mediterranean.

Tyrian purple is extracted from the mucous glands of the Murex snail, found in the Tyre region.

Purple: A Symbol of Power

Because only a tiny amount of dye could be harvested from each snail, Tyrian purple was incredibly rare, valued at three times the price of gold.

In the Roman Empire, purple was designated as the emperor’s color, reserved exclusively for the imperial family.

When Christianity became the state religion of Rome, the Catholic Church adopted this tradition, with purple symbolizing authority for popes and cardinals, earning the name Royal Purple.

The Rise of Synthetic Dyes in the 19th Century

For centuries, dyes were a symbol of wealth and power. But in the late 19th century, synthetic dyes revolutionized the industry.

In 1856, an 18-year-old student at London’s Royal College of Science, William Perkin, was experimenting with synthesizing quinine (an anti-malaria drug) from coal tar, a byproduct of coal refining.

Although Perkin failed to synthesize quinine, he noticed that diluting a black liquid from his experiment with ethanol produced a purple hue.

Since purple dyes like Royal Purple were rare and expensive, he tested the liquid by dyeing silk, which held the color even after washing with hot water or soap.

This discovery led to the world’s first synthetic dye, named mauve, marking the dawn of the synthetic dye era.

Synthetic Dyes Flourish in Germany

While Britain, post-Industrial Revolution, was the world’s leading exporter of cotton textiles, it relied on indigo imports from India, limiting synthetic dye development.

Instead, Germany and Switzerland, emerging scientific hubs, became centers for synthetic dye innovation, particularly along the Rhine River.

German Dye Companies

Bayer and Sanofi-Aventis are now major pharmaceutical giants.
BASF is a leading global chemical manufacturer.

Swiss Dye Companies

Novartis is a modern pharmaceutical giant.

Colors Become Accessible to All

Red-based dyes like mauve, known as aniline dyes, were refined, giving rise to new colors.

• Mauve: The first synthetic dye
• Fuchsine: The basis for magenta in printing
• Alizarin: A vibrant madder red

In 1868, alizarin became a massive hit due to its ease of dyeing and colorfastness, leading to the decline of the madder plant industry, previously a global source of red dye.

By 1897, indigo, and by 1909, Tyrian purple, were synthesized and mass-produced, making colors once exclusive to the wealthy accessible to everyone.

From Dyes to Pharmaceuticals

German dye companies reaped huge profits from alizarin, and Bayer applied dye technology to develop aspirin (acetylsalicylic acid) in 1897.

Salicylic acid had anti-inflammatory properties but caused severe gastrointestinal side effects.

Aspirin was engineered to remain inactive in the stomach, converting to salicylic acid in the bloodstream, drastically reducing side effects (a type of drug called a prodrug).

Beyond pain relief, aspirin’s benefits in preventing heart attacks and strokes have made it a staple for over 120 years.

Expressing Colors with AI Illustrations

Now, let’s return to AI illustrations and experiment with color expression.
We’ll test eight colors by inputting their prompts into various image generation AI models to see how they’re rendered.

SDXL (anima_pencil-XL): Base Image

AuraFlow_0.3

Flux.1 [dev] (blue_pencil-flux.1-v0.0.1)

HiDream-I1-Dev

Qwen-Image

AuraFlow and HiDream Shine in Color Expression

New-generation image generation models excel at rendering colors, but I personally prefer AuraFlow and HiDream for their color expression.

AuraFlow’s version 0.3 includes improvements tailored for artistic expression.

HiDream, equipped with four text encoders, excels at accurately interpreting prompts and rendering natural results.

About HiDream

Useful Websites for Color Inspiration

Here are some websites to help you choose colors for AI illustrations:

Deep Colors

Deep Colors is a curated collection of rich, deep hues ideal for image generation. It includes the colors used in this post, offering subtle, sophisticated tones distinct from highly saturated colors.

Note: For colors like Coffee, entering the name might generate a coffee-related image, so use the color code (#5C4033) instead.

HTML Color Codes (Color Library)

HTML Color Codes is a resource for web designers, offering a clear and comprehensive guide to inspiring colors for your projects.

Conclusion: Synthetic Dyes Transformed the World!

• Colors were once symbols of wealth and power.
• Synthetic dyes made them accessible to everyone.
• AI illustrations respond vividly to color prompts.

Colors are deeply tied to human history, each with its own rich story of discovery.

Today, with tablets and digital art tools, we can create any color imaginable. Why not experiment with expressing colors through words using AI?
Thank you for reading!

References

Color Adjustments in ComfyUI

All illustrations in this post were enhanced with AI-driven automatic color correction and HDR processing in LAB color space.