Why a Mexican family serve yellow corn tortillas to their guests?

There's no specific reason why a Mexican family would always serve yellow corn tortillas to their guests. Here's why:

* Regional Variations: Mexico has incredible culinary diversity. Tortilla preferences vary greatly depending on the region. In some areas, white corn tortillas are more common, while others favor blue corn tortillas.

* Guest Preferences: A good host will take into account their guest's preferences. If they know a guest prefers white tortillas, they might offer them.

* Occasion: The type of tortilla used might depend on the meal. For example, flour tortillas are often used for tacos al pastor, while corn tortillas are more common for tacos de carnitas.

However, yellow corn tortillas are a staple in many parts of Mexico and are often associated with:

* Authenticity: Yellow corn tortillas are often considered the most traditional type of tortilla in Mexico.

* Cost-effectiveness: They are generally less expensive than white corn or flour tortillas.

* Versatility: Yellow corn tortillas can be used for a variety of dishes, from tacos to quesadillas to enchiladas.

It's important to remember that there's no "right" answer to this question. The choice of tortillas is ultimately up to the host and their guest's preferences.