I cover hair in almost all my analyses, and 100% of the time if it isn’t natural.
There is a fundamental misunderstanding when someone says that certain colors look good with their hair one way but not another. The misunderstanding is that the goal in choosing a color should be to make a superficial harmony based on your overtones. (i.e. “This goes with my hair”) This will be obviously wrong to the many cool or cool neutral people who have brown eyes and hair. Wearing most browns and colors with a warm, earthy undertone brings out blotchiness and flaws which are not present in the correct (cooler) colors. Other brown eyed brunettes, however, wear these colors with no detriment to their skintone. Why is that?
They have apparently similar overtones and completely different undertones.
Yet, because the concept of looking at your hair, skin, and eye colors to determine what colors work seems so simple, the idea persists. You can find more information on overtone in my colleague Terry Wildfong’s article here.
Eliminating Color Noise
Modern color analysis involves observing the simultaneous contrast effects on the face caused by colors with different qualities and neutralizing them to reveal the most flawless, youthful and healthy skin appearance. To do so, we must eliminate color noise during the analysis, such as that from hair color, makeup, etc. Once we know the area of color space that produces the best skin appearance, we can then evaluate hair and cosmetic colors. After all, these too, are colors worn on and around the face, and should adhere to the guidelines set forth during the analysis. It should go without saying, but natural color, being cut from the same genetic cloth as the skin, is always perfect. That said, women have many valid reasons for dying their hair. This can be either an enhancing and beautiful thing to do or disastrous depending on the viability of the color chosen.
The secret to your natural coloring and most becoming appearance lies in your undertone.
The only way I know of to discover your undertone with certainty is through a Personal Color Analysis: to drape you with specific, calculated drape colors in a neutral grey environment with controlled lighting, and a complete reduction of color noise, including that of the hair color.