Which hair color makes Drew Barrymore look younger, darker roots or true blonde hair? Photo: Getty Images

A few days ago, I caught a glimpse of myself in the mirror at a department store. I had to do a double take. Was that really me?

I looked old and weathered, not to mention tired.

I normally don't feel like I look old (weathered and tired on occasion, especially after a long day at work or a mom's night out). I approached the mirror in horror--my complexion looked as rough and dull as a worn out doormat. Was I sick or was it was just me?

The next day I loaded up on my favorite bronzer (it always helps me feel radiant and youthful) and swiped on a bright pink lip gloss (another complexion pick me up staple). I still looked anything but luminous.

What was going on? Did my mid-thirties age finally rear its head?

As I went to pull my hair back into a ponytail, it clicked--could it be my hair color? With dark roots a mile long and grays popping out everywhere, was my hair making me look old?

"Absolutely," says Kyle White, lead colorist at Manhattan's Oscar Blandi Salon and colorist to some of the worlds most noted celebrities. "When your hair is too dark, it accentuates every last line. And when it's too light, it can wash you out and age you," he notes.

White, along with many beauty experts, is a firm believer that hair color is the single greatest tool available to women in their quest for youth. It instantly boosts your appearance -- brighter eyes, more radiant skin -- without the pain, irritation, downtime or price tag (a box of home hair color is approximately $10 while salon services can range from $80-200).

He also points out that as we age, our hair gets darker and loses its natural luster (shiny hair is a hallmark of youth). Adding warmth with highlights or treating hair to a shine-enhancing gloss immediately changes the way we feel and look. "We feel younger after having our hair colored because it's the hair of our youth, back again," explains White.

Hair color also adds fullness, which for women with thinning hair is a major bonus.

Here are White's tips to color yourself young:

1. Find a picture from your childhood and copy that hair color. "Nine times out of ten that is the color that flatters you most," says White.

2. If you have dark brown or black hair, try chocolate brown, caramel or toffee highlights. "They add dimension, open the face and instantly make you look fresh and radiant," explains White.

3. If your hair is light brown, face-framing, dark golden blonde highlights will enrich the complexion, creating luminosity and the illusion of lift.

4. As we age, blonde hair has a tendency to become ashy and dull. Pale yellow highlights ("Think the color of melted butter," notes White) bring out the warmth in the complexion, which naturally makes us look younger.

5. There should always be a contrast between your skin and hair color so you don't look washed out or too plate-both of which make lines, wrinkles and spots appear more obvious.

In my own very scientific analysis, to validate the notion of hair color-as-the-fountain-of-youth, I pulled my hair into a tight ponytail to expose only my dark, dreary roots. I polled the women in my office, and all agreed: dark hair completely aged me.

I immediately called White to book an appointment. A few strategically placed highlights later, it was confirmed that I definitely looked "a good 5 years younger."

Roger that.

Now, find out the best way to communicate with your hair colorist to get the results you want.

And click here to find out 4 common bad habits that can age you by 12 years!