Introducing FUS3™: The Technology behind Maintaining Cool Tone Brunette Hair

The perfect cool brunette is the definition of modern sophistication. Yet, achieving that effortless ‘quiet luxury’ hair color is often a struggle for both stylists and clients. The challenge isn’t just authenticity—it’s longevity. Everyone wants a signature cool tone that refuses to fade or turn brassy weeks after the appointment.

That’s where the FUS3™ shades come in. Browns that glow, and cool tones that melt into glazed reflection

The Challenge: Why Cool Tone Brunette Hair Fades

Keeping cool tone brunette hair​ from turning brassy or warm over time has always been the challenge with cool brunettes.

The reason why? Many cool hues are built on bi-pigment structures that lack the molecular stability to remain anchored, especially in porous hair. These traditional molecules lead to faster washout. As traditional pigments wash out more easily, cool tones fade and warmth returns.

It’s a structural limitation, not a formulation one. That’s why we have developed a brand new technology that will slow down the wash out process of cool tones

Introducing FUS3™ Technology: The Science of “Fuse”

Every shade is powered by FUS3™ Technology—a fusion of color performance and hair care science. This innovation redefines color tenacity, extending pigment longevity for lasting cool tone brunette results and stronger client loyalty.

FUS3™ (pronounced “Fuse”) is a patent-pending technology designed to lock cool tones inside the hair fiber.

The breakthrough is thanks to tri-pigment color molecules. Unlike traditional bi-pigment formulas, FUS3™ builds larger, more stable tri-pigment color molecules. In this new triple dye network, cool tone brunette hair​ keeps its shade longer as color molecules interlock more effectively to anchor within the hair, dramatically improving retention and resistance to washout.

The result? Activated coolness that lasts up to 10 weeks (based on 3 washes/week), far outperforming traditional color without FUS3™ technology.

FUS3™ also provides enhanced coolness over time with three color benefits:

• Richer brown hues
• More vibrant cool tones
• Deeper color intensity

While traditional pigments wash out easily, FUS3™ technology actively delays post-service brassiness. This ensures salon-quality results and cool-toned brunette hair that lasts weeks longer.

How to Maintain Cool Tone Brunette Hair with The FUS3™ Collection

FUS3™ technology is available in 6 new shades that span across 3 color technologies:

Revlonissimo Colorsmetique™ Permanent Color:

• 8 Light Brownish Brown
• 8 Medium Brownish Blonde

Revlonissimo Colorsmetique™ High Coverage Permanent Color:

• 8 HC Dark Brownish Blonde
• 8 HC Light Brownish Blonde

Color Excel: Alkaline technology – Tone-on-Tone:

• 81 Dark Brownish Ash Blonde
• 9.82 Very Light Brownish Iridescent Blonde

These 6 new shades are the key to unlocking the full potential of FUS3™ technology, empowering you to master signature services like Cold Brew.

Naturalization & Cold Brew

The Cold Brew technique is for brunettes seeking modern luminosity and blondes ready to move to a richer hue. Deepen, glaze and illuminate your clients’ hair with this naturalization technique.

Inspired by the tones of iced coffee, this approach blends espresso depth with glazed, light-catching reflection. FUS3™ pigments keep that cool tone brunette hair​ locked in, so the glaze doesn’t wash out into warmth.

Frequently Asked Questions about Cool Tone Brunette Hair

How long does FUS3™ technology keep brunette hair cool?

FUS3 technology provides up to 10 weeks of activated coolness by locking hair​ pigments Into larger molecules inside the hair. This is considering 3 washes per week, versus traditional coloration without FUS3™ technology.

Is this technology suitable for blonde clients going darker?

Absolutely.  FUS3™ technology is perfect for bronde naturalization, enriching the hair with violet pigments and cool reflections while maintaining dimension. The tri-pigment structure ensures the transition stays balanced and cool tone brunette hair​ stays that way.

What types of hair is this technology suitable for?

Regarding the fact that depending on the hair type and % of grey hair, some shades are more suitable then others but provide comfort in knowing that there is a shade for everyone.

Authenticity is the new aspiration. If you are inspired and ready for a shift in color to a new refined version of you, then head to your stylist or use our handy hair salon finder to get your own cool tone brunette hair​ shade!

If you are a client, head to our Revlon Pro Shop to stock up on all of the color and care products that you need. For more trends, education, and tips, head to our exclusive 24/7 educational platform,  #AlwaysOn. Perfect for all your go-to seasonal shades, technical formulas, and trend breakdowns to keep your creativity flowing behind the chair.