A Formulators Guide to Choosing the Right Colorant

Dye, Pigment, or Liquid Polymeric Colorants?

A Formulator's Guide to Choosing the Right Colorant

When you think of color, you likely focus on the visual aspect and may not consider its impact beyond selecting a shade. Yet the colorant you choose ripples through nearly every level of a product lifecycle: development, regulatory filings, manufacturing, transportation, and branding shelf appeal. Pick the wrong colorant, and you're troubleshooting stained equipment or faded product weeks before launch.

It's important to look at the entire colorant landscape to understand what your product might need. But first, let's start with the fundamentals.

What are colorants?

Dyes: Dyes are soluble colorants that dissolve into a solvent or water to deliver color at the molecular level. That solubility gives you bright, transparent shades. The trade-off? Dyes are designed to color textiles[LB2.1]. Their functionality also limits compatibility, and they tend to migrate, leaving marks on surfaces, skin, equipment, and fabric that are difficult to remove.

Pigments: Pigments are insoluble solid particles dispersed throughout a material rather than dissolved in it. Because they resist dissolving, they're designed to be insoluble, which is precisely what makes them difficult to work with in liquid systems. They offer stronger lightfastness and opacity than dyes, but they require dispersion equipment, can settle over time, and are notorious for staining hard surfaces, skin, and production equipment.

Liquid polymeric colorants: This is where the color chemistry fundamentally changes. Liquitint^™ polymeric colorants bond a chromophore—the color-carrying molecule—to a polymer backbone. The result is a liquid colorant that achieves total water solubility, low viscosity, and a non-settling, non-blocking format. Critically, Liquitint^™ colorants are designed to have low attraction to most surfaces, directly addressing the migration and staining that make traditional dyes and pigments so difficult to manage. You get the brightness of a dye with a dramatically cleaner handling profile.

Three approaches with three very different outcomes for your formulation. Understanding your options helps inform your color needs and how to best source color for a specific purpose.

Where are colorants used?

Colorants do far more than make products look good. Across industries, color does real work—signaling safety, communicating product identity, and reinforcing brand recognition.

Home and laundry care: Detergents, fabric softeners, and cleaners rely on color for brand distinction and shelf appeal—without staining packaging, equipment, or the clothes themselves.
Agriculture: Seed coatings use color as a safety and traceability signal, clearly distinguishing treated seeds from untreated ones and supporting accurate application.
Polyurethanes: Foams, coatings, and elastomers need color that integrates into a reactive chemical system without compromising the final material's performance.
Coatings and inks: Architectural and industrial coatings depend on color consistency and durability over years of exposure to light.
Personal care: Shampoos, soaps, and cosmetics demand colorants that perform in water-based systems while meeting increasingly stringent ingredient scrutiny.

No matter the application, the colorant has to perform within a formulation without creating problems downstream.

What challenges do colorants face?

Every colorant carries trade-offs. For R&D and product development managers, three issue themes tend to surface during product development, making colorant selection a critical element to get right.

Regulatory challenges

Ingredient scrutiny continues to rise, and colorant ingredients are not exempt. Some traditional dyes and pigments can carry heavy metal or chemical impurities that complicate safety data sheet (SDS) documentation, trigger labeling obligations, and create compliance risk. In the European Union, products using biocide are subject to strict governance as mandated by the Biocidal Products Regulation (EU) No 528/2012--making a strong case for biocide-free ingredients. As regulations evolve across the U.S., the EU, and other markets, a colorant that passes today's requirements may be subject to reformulation tomorrow.

That's why forecasting regulatory profile matters from the start. Choosing colorants engineered without heavy metals—and supported by transparent, thorough documentation—helps you stay ahead of shifting requirements rather than reacting to them.

Technical limitations

Two technical issues catch formulators off guard more than any others.

Water removal changes color: When your process concentrates a formula or drives off water, soluble dyes can shift in shade or intensity. What looked right in the lab can drift out of spec at scale, leading to rework, delays, and eroding confidence in your color-matching process.

Light exposure causes fading: Lightfastness, a colorant's ability to resist color degradation under light, varies widely across types. Many dyes fade or degrade once exposed to sunlight or ultraviolet (UV) light. Pigments generally hold up better, but only when dispersed correctly and consistently. Either way, poor lightfastness shows up as a quality complaint after your product reaches the shelf—long after you've moved on to the next development cycle.

Production difficulties

Dyes and pigments are both well known for staining production equipment, surfaces, and the hands of the people working with them. Powder colorants create dust, while pigments require dedicated dispersion steps and can settle or block process lines. Each of these factors adds cleaning time, production downtime, and cross-contamination risks between batches—real costs that rarely appear in a spec sheet but always surface in your operating budget.

Here's how the three approaches stack up across the attributes that matter most in development and production.

Attribute	Dyes	Pigments	Liquitint^™ colorants
Physical state	Solid or solution	Solid or dispersion	Liquid
Water solubility	Low to moderate	None	Total
Color appearance	Bright, transparent	Strong, opaque	Bright, clear
Lightfastness	Moderate	Moderate to high	Moderate
Staining	Moderate to high	High	None to low
Handling	Can require dissolving; dust risk	Requires dispersion; can settle	Low viscosity, non-settling, non-blocking
Migration/Bleed	Tends to migrate	Low	Resists mgiration
Heavy metals	Possible	Possible	None

Why Liquitint™?

At Milliken, we're fascinated by the difference a single molecule can make. That's why we engineered Liquitint™ polymeric colorants to balance the trade-offs that have long forced formulators to compromise—either accepting staining and handling complications from dyes or working around the insolubility and dispersion demands of pigments.

By bonding color to a polymer backbone, Liquitint™ delivers benefits that neither dyes nor pigments can match in full.

Easier handling: A liquid, low-viscosity, non-settling, and non-blocking format that simplifies dosing, requires no premixing, and helps eliminate equipment staining and dust that slow production and increases cleaning costs.
Cleaner formulation: Total water solubility with bright, consistent color strength—and none of the heavy metals that complicate compliance documentation or SDS filings.
Reduced staining and migration: Polymer-bound chemistry designed for low surface attraction, resisting the bleed and staining common to traditional dyes, even at high color loadings. Concentrated colors can be cleaned up with cold water.
Formulation flexibility: Tailored solubility, reactivity, and compatibility to fit your specific system, from detergents and personal care products to polyurethanes and industrial coatings.
Mindful chemistry: No heavy metals and high color loading in a chemically compatible, environmentally considered package.

Color shouldn't be the variable that derails your launch timeline or adds unexpected cost to your production line. It should be a tool you control, and with Liquitint™, it can be. Let's put color to work for your next formulation.