Knowing the true color of your skin is primarily about finding the underlying color of your skin, which is the key to buying the right glasses for the perfect look.
SKIN UNDERTONES
When shopping for foundation, you’ve probably heard the terms "cool," "warm," or "neutral" to describe how a shade will look on skin. Those terms refer to your skin’s undertone and are used to determine which foundation shade will match it the best. The following are the meanings of these terms:
HOW TO IDENTIFY THE UNDERTONES OF YOUR SKIN
Look at the vein inside your wrist (in natural light). Are they blue or green? If your hair looks bluer or almost purple, you may be a cool color. If they look greener, you may be warm. If you can't tell if they are blue or green, chances are you tend to be neutral

The other way to determine your skin undertone is the effect of the sun. At times you forgot to wear sunscreen outside, did your skin turn golden-brown, or did it burn and turn pink first? If you burn easily, it’s likely that you have cool-toned skin. If you get an envious golden tan, you likely have warm-toned skin.
THE PERFECT GLASSES FOR YOUR SKIN UNDERTONE
The easiest way to know what color is best for your face is to try different colors as much as possible.