Why is it not possible to identify your undertone (cool/warm) by veins or dark circles?

Although widespread, the idea that it's possible to determine skin undertone by observing the color of veins or dark circles is one of the most common myths in image and makeup consulting. Personal color analysis works with color-light , not color-pigment —and it's this difference that changes everything.

What is undertone and how does it reveal itself?

Skin undertone is the base temperature that influences how colors reflect on it — it can be cool (with a bluish influence) or warm (with a yellowish influence). It is not something we see directly, but something we perceive through the interaction between light and skin .

IMPORTANT ADDENDUM!

Temperature is one of the three elements sought, and in turn the basis of classification, to determine one's personal color palette. The other two are depth and saturation. To learn more, click here.

When we perform a personal color analysis, we use specific fabrics under neutral, controlled light to observe how the skin reacts: whether it gains radiance, balance, and harmony (indicating a match), or whether it appears tired, yellowish, or grayish (indicating an unwanted contrast).

👉 This process observes light reflection , not deposited color , which completely differentiates it from empirical methods such as the “vein test”.

Light Color vs. Pigment Color: The Technical Reason Behind the Error

Color theory distinguishes two systems:

• Color-light (additive model / RGB) – this is what occurs when light strikes and reflects off surfaces. By combining colored lights, we form lighter hues (the total is white).

• Pigment color (subtractive model / CMY or RYB) – this is what occurs in paints, shadows, blood, or veins. Mixing pigments tends to darken and neutralize the color.

🔹 When we look at veins or dark circles, we are seeing pigments under layers of skin — that is, the color absorbed and reflected under biological and lighting conditions that do not represent the actual light on the skin.🔹 The same goes for makeup based on “undertone”: when trying to correct something by observing pigment (such as purple, green or blue), without considering the light and the facial complexion, the result tends to clash or “heavien” the face.

📘 As Science of Color explains, color perception changes depending on the light source and the medium on which it falls — pigments absorb part of the light, while living surfaces (such as skin) reflect it in a variable way depending on the temperature and light intensity ( Science of Color, Google Sites ).

Why “green veins” or “bluish dark circles” don’t define the undertone

Veins and dark circles are pigmented structures located at different depths of the skin. Their color depends on biological and optical factors, such as:

• Thickness and transparency of the skin,

• Amount of melanin,

• Blood oxygenation,

• Type and intensity of ambient light,

• Blood pressure.

In other words: there is no direct relationship between the color of the veins and the actual undertone of the skin . The same undertone can display bluish veins under cool light and greenish veins under warm light.

Researcher Laura D. Smith (2021), in her study on color perception in the epidermis, explains that light reflected by the skin undergoes optical distortions that alter the perception of hue depending on the environment — which makes any assessment without light control unreliable (Smith, Color Science Review , 2021).

The role of light in personal color analysis

During a personal color analysis , the room is prepared with neutral light (usually between 5500K and 6500K) to ensure technical and consistent observation. The fabrics used in the tests—called drapes —reflect colors accurately, allowing for direct comparisons of how light strikes and reacts on the skin.

This methodology is based on principles of applied colorimetry and the theory of Johannes Itten , who studied chromatic harmonies and their relationships with temperature, saturation and contrast (depth) (Itten, The Art of Color ).

The most common mistake: makeup based on the “vein test”

It's common to see tutorials suggesting foundation, concealer, or blush shades based on the color of veins or dark circles. But when undertones are interpreted based on pigments, the makeup tends to misalign with the skin —the result can be grayish, artificial, or too contrasting.

For example:

• A person with a warm undertone may appear pale or “lifeless” when using a cool-toned foundation.

• A person with a cool undertone may appear orange or yellowish with warm undertone products.

  Extremely common mistakes, unfortunately.

What really makes a difference is observing how the light reacts on the skin with each color applied , not the apparent color of a vein.

Conclusion

Undertone isn't revealed in veins or dark circles, but in the skin's relationship with light . Identifying your ideal colors requires technical observation, a controlled environment, and sensitivity to perceive the nuances of light reflection on the skin.

➡️ Therefore, personal color analysis is always performed using neutral light, specific fabrics, and professional evaluation—not by pigment deduction. It is this care that transforms the process into a true discovery of how light reveals your beauty in a natural and harmonious way.

📚 References

• The Art of Color — Johannes Itten

• Science of Color (Google Sites) – How Colors Mix: Light vs Pigment

• Smith, L. D. (2021). Color Perception in Human Skin under Variable Lighting. Color Science Review.

• Color Analysis. Wikipedia