Dull, lackluster hair color can add years to your look. But covering those pesky grays, choosing a new shade, or just brightening your natural strands can instantly turn back the clock. From DIY to professional, and from natural treatments to those of the standard chemical variety, here's a rundown of your hair coloring options.

To find the shade that will make you look younger, start by backing up about 10 years. What was your natural hair color when you were younger?

"Look back at old pictures to the palette of your childhood, when hair color tends to have a lot more natural dimension than when you've aged," says Eric Muroski, a colorist at the Marie Robinson salon in New York City. "The shades in that mix will still likely work best with your skin tone."

Another trick for finding your best hair color: Stand outside to see which colors emerge when the sunlight hits your hair. These shades are a great place to start.

Some dyes involve more commitment than others. Here's a rundown of what type of color to pick and when:

Semipermanent Color: Low-commitment and nondamaging, semipermanents usually have no ammonia or peroxide to permanently alter your hair's structure. Within 8 to 12 shampooings, you should be back to your normal shade -- unless you're blond: "If you're trying out a semipermanent brown or black on light hair, the color isn't going to go away so quickly," Muroski warns. Use If: You're going drastically darker.

Demipermanent Color: Though it contains a small percentage of peroxide to enable a greater degree of pigment penetration (expect results to last 6 to 8 weeks), demipermanent color is still only minimally damaging. But stay within a shade or two of the color you have now -- you can always go darker on round two. Use If: You're going a shade darker.

All-Over Permanent Color: This is fine for home use if you're only going a shade or two lighter than your natural hair color. But going from dark brown to blond or honey to platinum is best left to the experts. If you want more dramatic lightening at home, consider going a shade or two lighter all over, then adding highlights. Use If: You're going lighter.

At-home color is a great dyeing option, but make sure you're getting the most out of that box that you can. Start by making sure your hair and skin are ready for the new hue.

If You're Using Permanent Color: Don't wash your hair for one to two days before coloring so your scalp will build up a natural oil barrier that helps prevent irritation.

If You're Using Semi- or Demipermanent Color: Shampoo and dry your hair just beforehand, but skip conditioner. This puts the hair in its most porous state, allowing it to soak up the most color.

Apply a Protective Oil to the Area Just Around Your Face: You'll help prevent staining around your hairline, a surefire sign of a bad dye job, and, what's worse, a cause of skin irritation.

Well-conditioned silver strands can work in your favor if it's your all-over color, but a few grays sprouting here and there can make you appear older.

If you're simply trying to cover grays, you can just match your current shade -- unless, that is, you're blond. If you're blond or a very light brown, try a shade darker for full gray coverage.

Lighter streaks in the top layers of your hair and around your face mimic lightening from the sun -- an effect that gives your face a more youthful glow.

Unlike all-over color, which leaves a solid line of demarcation as your hair grows out, properly weaved-in highlights leave no such line, making them one of the most natural-looking color options. 

You can even use highlights to make your entire head look lighter over time. Adding a few subtle highlights gradually will create an overall lightening effect, with minimal damage. 

A shiny, even new hair color will shed years from your look, but an overprocessed, splotchy dye job will make you look like a clueless teenager. A common culprit for uneven color catastrophes is leaving the color on too long.

Never leave the colorant on longer than recommended. It won't get richer, just inkier -- the opposite of a more youthful look. When you color on your own, start the timer as soon as you begin applying the product. 

The only truly natural, plant-derived, permanent hair color is henna -- and not even every shade of it. John Masters, of the eponymous salon and beauty brand, says, "The lone shade that's 100 percent natural is that orange-red one, which doesn't suit many people."

Use it only if you're hoping to warm up and redden your hair a bit: At-home hennas are full of red tones, Muroski says, so they aren't good for simple darkening.

If you want to try henna, avoid over-reddening by leaving the solution on for 5-to-10-minute increments. Note: If you're blond, skip the henna altogether, unless you want pumpkin-color hair.

If you're looking for natural products but not up for henna's red glow, vegetable dyes are the next best thing; look for them at health-food stores. Most still contain nonvegetable content, so you (or your colorist) should scan the ingredients. What you likely won't find in these picks are resorcinol, which helps adjust tone but can harm skin, and ammonia.

Would-be blondes have bleach to blame for blisters and burning on sensitive scalps, as well as lightheadedness. But the bleaching processes have improved: "The amount of ammonia in dyes and bleaches is very slight now compared with 20 years ago," says Eva Scrivo, a New York City colorist, referring to the potentially skin-irritating chemical used in products to help color penetrate hair. "In the '60s, products contained 20 percent ammonia, but now they're down to 1.5 percent."

Some new bleaches don't contain any ammonia at all -- and still work well if you have light to medium brown hair. If you're worried, try a patch test before subjecting your whole scalp to the dye in question, or take a lighter approach, such as highlights, where no chemicals touch the scalp.

The same lackluster locks you reenergized with a boost of color can come back if you don't care for them correctly. Seek out shampoos specifically designed for color-treated hair. Harsh surfactants, such as detergents, can strip pigment, leaving color faded and dull.

Also, keep an eye on your roots: Dark (or light) roots sprouting at your part look messy and unkempt. If you've got a streak of unmatching strands, it's time to redo your color.