Temporary hair color is quick to apply and the quick to fade colors last for five to ten shampoos and are applied as rinses, gels, sprays or mousses. While it certainly sounds like less of a commitment than permanent dye, temporary hair color should be used with just as much caution. Here are some pros and cons:
PROS:
If you like to be the first person you know to try every trend, temporary hair color will let you change your hair color quickly, easily and often. You can also use a temporary hair dye job as your training ground for a permanent one later. If you're unsure just how dark you want to go, try the temporary color first to see how it looks. If you like it, choose a permanent color to match once the temporary hue rinses out.
Another great plus is that temporary hair color is less damaging than permanent dye. Since it doesn't use the same harsh chemicals and doesn't penetrate the hair shaft as deeply as permanent dye, it can in fact end up making your hair appear healthier, giving it instant shine and body.
It's also super easy to use. It's an all over rinse and never needs to be touched up-by the time roots would show, all of the color has already rinsed out. Once the color fades, you reapply in the same fashion.
CONS:
Temporary colors can't lighten your hair. They only coat the surface of your hair (some semi-permanent dyes penetrate the hair shaft slightly) and don't include any ammonia or peroxide that are needed to strip your hair of its natural color. So if you want a lighter shade, you'll have to try a permanent dye.
Even though the box says it's only temporary and promises that color will rinse out in a few shampoos, that's not always the case.
Even though semi-permanent dye is the best choice for dry and damaged hair, unhealthy locks can set you up for disaster. The damaged portions of hair tend to pick up color more quickly than undamaged sections so your color could go on unevenly leaving you with streaks and splotches. Also, if you have previously bleached your hair or have a naturally light color, be careful. Dye tends to hold steady to lighter colors and is simply more noticeable if parts don't wash out completely.
And finally, women often forget about one problem with temporary hair color--simply the notion that they are temporary. You might think on a whim that purple streaks are a great idea because it's only temporary, but after the fact you might decide you can't even live with the results for the five to ten shampoos the new look will last. No matter what type of dye you have in your hand, think before you color!