I don't know my undertone

The undertone of your skin does not refer to your skin color (the superficial color of your skin)
But your undertone is determined by the amount of pigment in your skin and shines through your skin. The undertone does not change with exposure to the sun.

There are three undertones (which apply to all nationalities), namely:

A cool undertone
A neutral undertone
A warm undertone

When you know whether the undertone of your skin color is warm or cool, you also know which colors best suit your skin type. And you can choose the most suitable competition bronzer.

This also applies to (posing) clothing.
Everyone has a piece of clothing in the closet that you know that the color looks very good on you, or not. This has everything to do with the undertone of your skin.

If you use a competition bronzer that doesn't match your skin tone, you can look gray or orange.

- A bronzer with a lot of yellow pigment will look very yellow or orange on a cool skin tone.
- A bronzer with a lot of pink pigment will look gray on a warm skin tone.

So: If you have a cool undertone, your skin undertone is bluish. choose a color with a blue undertone, avoid colors such as orange and yellow. If you have a warm undertone, your skin undertone is yellowish. Then choose colors with a yellow undertone. If you have a neutral undertone, you're in luck and most colors look great on you.