H-Linx TECH: The First Seven Days After Coloring
An Early Care Approach for Long-Lasting Hair Color and Hair Feel

The First Seven Days After Coloring: The Gradual Changes During the Transition Phase

The Satisfaction Right After Coloring—and What Comes After

In a consumer survey conducted by Kao, many respondents report that right after coloring, their hair color looked vibrant and their hair appeared smoother and shinier. At the same time, many still express concern about damage.
But in reality, that just-out-of-the-salon look doesn‘t last long. Many respondents find that after each wash, and within just a few days to around a week, the ends become drier and frizzier.

Over time, the color continues to fade, and as a yellowish tone starts to appear, it makes the hair look even rougher and more damaged. This trend was also observed in the research.　 The question is: what causes these changes?

A New Discovery: Understanding the Transition Phase—How Hair Damage Progresses During the First Seven Days After Coloring

After coloring, dryness and difficulty managing the hair often appear after some time. To better understand what causes these changes, Kao continued its research and arrived at a key insight: the common assumption that hair damage occurs mostly during the coloring process does not fully explain what happens afterward.

This led to a new understanding that damage, long thought to occur mainly during the coloring process, continues to progress within the hair even after coloring.
Over time, these ongoing changes within the hair accumulate and eventually appear as dryness, frizz, and a loss of manageability around a week later.

H-Linx TECH: Understanding the Transition Phase to Enhance Hair Beauty

Knowing How Damage Occurs Is the First Step Toward Maintaining the Beauty of Color-Treated Hair

Hair-color damage progresses quietly inside the hair not only during the coloring process itself, but also over the seven days that follow, before it becomes visible on the surface. At this stage, these changes are not yet clearly felt as damage—the hair remains in a fluctuating, unsettled state.
This “transition phase” is a period in which changes in color and texture overlap, leaving hair more prone to damage.

These changes begin in the protein bonds within the hair, which help maintain its structure. During coloring and in the days that follow, these bonds gradually weaken, even if nothing looks different on the surface. As these changes accumulate, they begin to appear as signs such as dryness and roughness.

It is this transition phase that needs to be understood seven days after coloring.

Caring for hair during this transition period in the right way helps maintain color and support the appearance and feel of the hair over time.
H-Linx TECH was developed from this idea.

Built on a deep understanding of these internal changes, H-Linx TECH helps create the conditions for longer-lasting color, with smoother, more manageable hair.

Early Care—Staying One Step Ahead After Coloring for Beautiful Hair

Damage That Develops After Coloring—Introducing Early Care as a New Technology

After coloring, damage continues to progress quietly over the days that follow—even before it becomes visible. This is why early care is so important.

There are many effective after-care products, such as hair masks and oils, that help manage visible signs of damage, including dryness and frizz.

The focus is on early hair care before visible signs of damage appear—helping create a condition in which damage is less likely to develop.

With H-Linx TECH, care begins before symptoms appear—helping to avoid the cycle of damage and follow-up care, and supporting the appearance and feel of the hair for longer after coloring.

The First Seven Days After Coloring—Why Early Care Matters

As the research progressed, Kao focused on a key point: the changes during coloring and those in the seven days afterward are not the same.
This led to the idea of delivering the right ingredients at the right time for each type of damage.

Using a treatment after coloring helps protect the hair from damage that gradually develops over the seven days that follow.

With this treatment, we achieved a technology that keeps the hair from feeling damaged and protects your hair for the future, rather than just treating symptoms after they appear.

Keep Colored Hair Looking Beautiful and Feeling Smooth with H-Linx TECH

Caring for Hair Before Damage Appears

H-Linx TECH is unlike conventional damage care: by focusing on early care during the transition phase after coloring, it helps create a state in which hair is less likely to feel damaged.
This means you can preserve the beautiful color and hair feel, keeping it smooth, controlled, and easy to manage—not just for the first seven days, but for long after.

With this technology, the effects of the transition phase can be better managed, helping maintain the appearance and feel of freshly colored hair for longer as the color changes more gradually and naturally over time.

There are more moments than you might think when you see yourself—not just in photos from special occasions like trips, events, or anniversaries, but in everyday life as well.

In a photo with friends, a reflection in a shop window, or the mirror each morning, there are countless moments when you see yourself—and your hair.

And in those moments, when you catch yourself thinking, “My hair actually looks really good today,” it lifts your mood and helps make the whole day feel better.

That feeling can give you more confidence, make you want to get out and see people, and bring a more positive energy to your day. H-Linx TECH is designed to support more of those moments in your everyday life.