Experts say these tattoo colors cause the most reactions

(CNN) – Are tattoos taboo? Apparently not for millennials.

Nearly 40 percent of people between the ages of 18 and 29 have some kind of tattoo, according to the Pew Research Center.

Tattoos are part of our culture. As popularity grows, so do the risks.

Tattoos can trigger allergic reactions, especially the ink. The common colors that cause the most problems is yellow and red.

Yellow is associated with sun sensitivity by forcing some to cover their tattoos when out and about.

Experts say the photosensitivity typically fades after a few years.

A reaction to red is more prevalent.

For many, the response is mild, including redness, swelling, or an itch that typically can be treated topically.

Others can experience a severe reaction that could potentially turn the tattoo experience into a nightmare.

According to the American Academy of Dermatology, an allergic response can happen immediately.

In some cases, your body may respond weeks, years, or even decades after you get inked.

If you are thinking about getting a tattoo, research the risks, and make sure you always wash your hands when caring for your new ink.