Do you find yourself shopping for concealer and looking at a rainbow of colors, wondering what the difference is if you buy a pink, yellow, or green? I had this problem and never knew what they were used for so I limited myself to purchasing the nude shades which literally were the same as my skin tone for fear that I would start to appear clownish with the rest. Fear not, however, because I'm going to tell you exactly what they're all for so don't be afraid to add them to your arsenal of blemish and imperfection coverage.
In general, concealers hide dark circles, scars, pimples, and really any skin flaw you can think of. It's always important to consider whether or not your concealer is of adequate quality and won't cake on your face, as this will make you flaws stand out even more (not exactly your intended result, is it?). Concealer colors are all about neutralization, since most of our skin's imperfections have a color hue to them. For example, your under-eye circles tend to be blueish in hue, many people have redness on their faces, and pimples can be plenty of colors. As for imperfections that aren't affected by color, such as wrinkles and fine lines, we would stick to using the neutral concealer that just matches your skin tone and foundation.
Let's take a look at the color wheel because it holds the key to the mystery that explains what all the various colors of concealers can do for your skin. The theory is that colors on the opposite end of the spectrum (so right across from each other, the way violet is to yellow) cancel out or neutralize each other. Therefore, if you had a yellowish blemish on your face, you would want to use the lavender concealer to neutralize the color before you put on your foundation (foundations generally will not cover up blemishes unless you use a ton, and rather than making your face look like a kabuki mask, you should use concealer). Mint green concealer is used to combat redness such as inflamed pimples and rosacea (redness due to capillaries being too close to the skin). Yellow shades are used to hide nasty veins that may be seen, and the same goes for orange shades which are usually for purple and blue bruises as well. Baby blue or lavender concealers are used to even out your skin, for example if you have bruises or birthmarks that you want to get rid of. The three general concealer colors are yellow, lavender and green. Yellow or apricot warms the skin color and counteracts discoloration on top of its already mentioned uses. Lavender concealer brightens dull skin and can even be used to conceal very dark under eye circles (but not in fair skinned people generally because the dark circles won't be dark enough and can be handled with yellow). Green concealer minimizes redness is general so this color is the most useful for people with red blotches or port wine stains around their mouth as well.
If you have tattoos and you want to cover them up without spending a pretty penny for your tattoo concealers, use the regular drugstore concealers but consider the color of your tattoo. If you have a blue tattoo, use a concealer that is yellowish and make sure that you have a waterproof formula as well as applying a translucent powder on top to set the product for the longest staying power possible.
Below is a collection of concealers that I am familiar with and that have worked well for me at a reasonable cost.