Single-Process Color vs. Highlights vs. Double-Process: What's the Difference?

Switching up your hair color is one of the most fun you can have when transitioning your look. Sure, getting a new manicure and experimenting with new makeup techniques can also feel exciting, but changing your hair color involves a different type of permanency which adds to the allure. And whether you're blonde, brunette, redhead, or don a bold shade of pink or green, you still have options. It's all about hair coloring techniques, such as single-process.

For the most part it boils down to highlights, single-process, or double-process. Each delivers different types of results, and within those there could be one that better fits your lifestyle. Highlights, for example, require touch-ups every two to three months, so it's worth factoring upkeep when deciding how you want to color your hair.

If this seems overwhelming, we understand. And dyeing your hair is not something you want to venture into with your eyes closed. That's why we spoke to two hair experts to break down everything there is to know about the different hair coloring techniques and how to pick which is best for you. Their insights, below.

What Are Highlights?

Highlights are an ideal option if you have a great base hair tone, and don't want to amend your natural hair color too much. Highlights are often the introduction to hair coloring since they enhance your hair by adding streaks that are a shade or two lighter than your natural color. They look the most dynamic when the stylist uses at least two different shades. You can also ask for face-framing highlights to brighten your complexion.

"With highlights, your colorist should be using more than one color, not just bleach," says stylist Darren Anderson. "Great highlights should be layered to produce tonal variations. There should be lights, mediums, and darks to create depth and translucence in the hair. Highlighting should be like painting a masterpiece, and you can’t do that with just one color."

There are four types of highlights: basic foil highlights, balayage or "hair painting," chunking or "piecing," and lowlights.

• Foil highlighting is the most traditional highlight method. The technique adds uniform color to hair, and it can be made streaky or well-blended. You can get many different shades for a natural look.
• Balayage or "hair painting," allows the stylist to add natural stripes of color to hair in large or small swaths. This is a great choice if you have a base color you love and just want to go a couple shades lighter in certain areas. You won't need to get your roots touched up as much with balayage as you do foils, and it grows out better than any other color option.
• Chunking, or "piecing," is when thick stripes of color are painted onto the hair. It was a popular technique in the '90s, but is still used today. 
• Lowlights allow the stylist to add darker shades of hair, and they're often combined with highlights. This can give your color even more contrast and dimension.

If you want to spice up a simple haircut but have very few layers, highlights are a great option. The style is particularly flattering on brown and dark blonde hair. "Highlights add dimension and can disguise gray on light brunettes to blondes," says Brown.

What Is Single-Process Color?

On the other hand, if you want to go several shades lighter or darker than your natural hair color, single-process (also known as all-over color) is the way to go. This process changes the color of your entire head of hair, giving you a new, one-dimensional tone that can be as dramatic or subtle as you like. 

"Single-processes or base colors are good for covering gray and is minimally damaging," says Brown. "They give you an all over one color, with little to no dimension. You may get slight variations of color if you use semi-permanent. "

Single-process color is a great choice if you have very short hair that can't be easily highlighted. It's also a nice option for adding warmth, which can boost your skin tone, or if you want to cover a considerable amount of gray hair. All-over color can complement a trendy haircut that may look a little too "let me speak to your manager" with highlights. It's also nice when you're trying to darken your hair in a uniform way. 

Keep in mind that due to root growth, all-over coloring will need to be touched up every four to eight weeks, while highlights can last up to two or three months.

Can You Get Both Highlights and Single-Process Color?

You can also get both highlights and single-process color. This is a good choice if you, for instance, want to cover gray hair but still want the extra dimension highlights offer.

"You can do both, but you may not get the highlights as light as you want," says Brown. "Or you hair can be drier or a little more damaged—but it can be minimal as long as it’s done correctly and with a professional."

Another thing to consider is the cost. In most salons, single-process color is cheaper than highlights. Additionally, single-color tends to be gentler on your hair than highlights. The bleach used in highlight formulas can cause damage, particularly if you have them done often, or use other chemical hair treatments.

What About Double-Process Color?

The alternative to single-process color or highlights is a double-process color. Double-processing changes your entire hair color while adding dimension and extra color through the second treatment.

"A double-process is platinum," says Brown. "Usually the harshest on the hair since you are stripping it completely to get platinum blonde. It’s best to have short hair or know that you will have to cut your hair after. "

Typically, the double-color process is used when you want to take dark hair much lighter. Stylists begin by bleaching out your natural hair color (which could take one or several hours) then apply the new color. It can also be done with an overall color, then a highlight treatment during the second stage. This process is often the secret to the great hair we see on many celebrities, but it comes at a price. Not only will you be paying for two separate color treatments—which gets pricey—but too much of it can lead to damaged hair.

"Your hair will feel very different after getting this done. You will need to take care of you hair after with conditioning treatment at minimum of once a week," says Brown.

The Final Takeaway

To decide which option is best for you, look at your natural hair color and how you can reach your hair color goal with the least amount of damage to your hair. "If you have gray and it bothers you, I say go for a single process," says Brown. "If you have slight gray or you are blonde with gray, highlights might be a better choice to disguise the gray instead of covering."

If gray hair isn't an issue, Brown says to consider highlights. "If you have no gray, I don’t recommend doing a single process unless you really don’t like your color—and maybe want to be a redhead or a richer brunette. I don’t recommend single process blondes, they tend to look flat and brassy," she says.

"If you are looking for a change, I say start looking at pictures to see what you like and go from there," she says. "Hair color is to enhance what you have—so have some fun with it!"