Skip to Content

What are the colored streaks under hair?

Colored streaks in hair have become a popular fashion trend in recent years. They allow people to add a pop of color and express their personal style. But what causes those colorful streaks under the hair shaft? Here’s an in-depth look at what creates those eye-catching effects.

The Hair Structure

To understand what causes colored streaks in hair, it helps to first look at the structure of a hair strand. Human hair consists of three layers:

  • The innermost layer or medulla – This is a soft core at the very center of the hair.
  • The middle layer or cortex – This makes up the bulk of the hair strand. The cortex contains bundles of keratin protein and melanin pigment that give hair its strength, texture and color.
  • The outermost layer or cuticle – This consists of overlapping scales that protect the inner layers. The cuticle controls shine and smoothness.

The amount and distribution of melanin pigment in the cortex is what gives hair its natural color. People have different amounts and types of melanin. The two main types are:

  • Eumelanin – This melanin creates brown and black hues.
  • Pheomelanin – This creates red and blonde hues.

When coloring hair, dye penetrates into the cortex and cuticle layers. How deeply and evenly it deposits or removes pigment affects the final color results.

How Colored Streaks Form

There are a few ways streaks of color can form in the hair:

1. Uneven dye penetration

Sometimes hair dye doesn’t penetrate evenly through every strand. This can happen if:

  • Hair isn’t evenly saturated with dye from root to tip.
  • Dye is wiped or rinsed off on some strands more than others.
  • Hair’s texture or porosity varies in different sections, causing uneven dye uptake.
  • Dye isn’t left on long enough to fully penetrate every strand.

When dye penetration is uneven, some strands end up more intensely colored than others. This creates a streaked look.

2. Multiple dye applications

Another cause of streaking is applying multiple rounds of dye in different sessions. For example:

  • Highlighting hair first then applying an overall color later.
  • Dyeing hair initially, then touching up the roots with dye after regrowth happens.
  • Adding different shades of dye on top of an existing color.

These layered dye jobs often leave hair with sections that are more saturated with color than others. This forms streaks of different hues.

3. Chemical processing

Chemical hair treatments can create color streaks by altering hair’s structure and porosity. For example:

  • Bleaching – Lightens hair’s natural pigment. Can cause streaks if bleached unevenly.
  • Perming – Curls the hair shaft. Can change how dye penetrates in different sections.
  • Straightening – Relaxes the internal bonds. Can affect dye uptake.
  • Relaxing – Straightens tightly curled hair. Can alter porosity and color results.

These chemical processes can strip color, make hair more porous or create textural differences – all of which can lead to uneven dye absorption and colorful streaking.

4. Sun exposure

The sun’s UV rays can alter hair color over time. Sunlight tends to lighten hair and can degrade artificial dye molecules. This can cause subtle, streaky changes in hue, especially in highlighted, colored or gray hair.

Common Types of Colored Streaks

Now that we’ve looked at what causes them, here are some of the most popular types of colored streaks people request:

Highlighted Streaks

This is created by applying lightening bleach or dye to small sections of hair. The highlighted pieces stand out against the darker base color. Babylights, for example, are fine highlighted strands that create a subtle, natural look.

Tonal Streaks

This is when streaks blend more smoothly with the base color instead of starkly contrasting. Going from a medium to light brown with babylights, for example.

Ombre Streaks

Hair is colored in such a way that the shade gradually gets lighter from the roots to the ends.

Balayage Streaks

The dye is painted on in sweeping sections for a soft, blended, natural look. The color transitions seamlessly from roots to ends.

Chunky Streaks

These are bolder, thicker sections of contrasting color. For example, 1-2 inch chunks of platinum blonde through dark brown hair.

Dip Dye Streaks

Only the mid-lengths and ends of the hair are dyed, leaving darker roots. The colorful streaking is concentrated on the tips.

How to Maintain Colored Streaks

To keep those eye-catching streaks of color vibrant and fresh, be sure to:

  • Use shampoo and conditioner made for color-treated hair.
  • Wash with cooler water instead of hot.
  • Limit washing to every 2-3 days instead of daily.
  • Use a sulfate-free shampoo to preserve dye.
  • Rinse with a mix of cold water and vinegar to seal cuticles.
  • Apply a deep conditioner weekly to hydrate strands.
  • Use a heat protectant before hot tools to prevent fading.
  • Wear a hat in sunlight to avoid color degradation.
  • Get a gloss or touch-up treatment when needed.

The Pros and Cons of Colored Streaks

Here’s a quick look at some of the key pros and cons of adding streaks of color to your hair:


  • Lets you experiment with fun colors without full commitment.
  • Adds visual interest and dimension.
  • Many techniques create a soft, natural look.
  • Doesn’t require as much maintenance as all-over color.
  • Can cover or blend away unwanted gray hair.


  • Roots may be obvious as hair grows out.
  • Can dry out or damage hair if overdone.
  • Fading can look uneven without occasional touch-ups.
  • Doesn’t work as well on very short hair.
  • Takes longer time and skill to achieve special effects.

Consult a Stylist

While streaked hair looks fun and creative, it does take skill to achieve the right look. Consult with an experienced hair colorist when planning any complicated coloring technique. They can assess your hair’s condition, advise what’s achievable, and skillfully apply dyes to create beautiful, long-lasting streaked effects.

With proper application and care, colored streaks can be a gorgeous addition to your personal style. Embrace the rainbow and go for it!