Let's break it down:
* De qué: This is a combination of the preposition "de" (of) and the interrogative pronoun "qué" (what).
* color: This is the Spanish word for "color."
* son: This is the third-person plural present tense of the verb "ser" (to be).
* tus: This is the possessive adjective "your" in the plural form.
* ojos: This is the Spanish word for "eyes."
So, the entire phrase literally translates to "Of what color are your eyes?"