These foundation testers are available for exotic skin with a yellow undertone.
Majeur, Jive, Emerald, Fenia, Dust, Santo
On the left you see some examples of models, so you can see if your complexion comes close to one of these photos. It doesn't matter if you don't have the exact same skin colour, as long as your complexion comes close.
If the colour blends smoothly without having a visible edge, you've found the right colour.
You can also see it well if you apply foundation to one side of your face.