The white stripe is the center stripe of the Mexican flag and contains the national coat of arms. In modern civic explanations, white is commonly associated with unity. It points to the idea of Mexicans forming one nation despite regional, social, and cultural differences.

In the older Army of the Three Guarantees symbolism, white was associated with religion, specifically the Catholic faith. Modern school and civic explanations usually emphasize unity instead. For a citizenship test, it is helpful to recognize white as the center stripe and remember its common modern association with unity.