Colored contacts are not inherently safe or unsafe. Actually, all contact lenses increase your risk to your health even when prescribed by your optometrist. But don't let that scare you away from trying to wear contacts. Many things in life come with the potential for risk.
If you educate yourself on contact lens safety, the risk of harm goes down dramatically.
Colored Contacts vs. Regular Contacts
All contact lenses pose a risk to your health. Think about it, you're putting something in your eyes and that could potentially lead to some unwelcome result right? Colored contacts are no different. If you follow the directions of an optometrist, or a contact lens manufacturer, your risk will go down, it's pretty simple.
Lenses don't hurt people, poor lens care & not listening to your body hurt people, or hurts yourself...
A contact lens can't really hurt you. But if the contact lens has bacteria on it, that could hurt you. If your contact lens is too big or too small for your eyes, that could hurt you as well... But wait, there's more!
If a contact lens is too big or small, it will let you know by causing pain or discomfort. If you feel any of those just remove the lenses right away. This is only really a concern when you're wearing colored contact lenses purchased without a prescription, often times they're not fit for your eyes. This isn't always a problem though, sometimes you just need to wear colored contact lenses for less time than you might wear prescription contacts.