Learn French: Elle choisit une couleur différente.

Choisir (to choose) is a regular -ir verb. To make the il, elle, or on (he, she, or it/one) form, you drop the -ir ending from choisir and add -it. So, it becomes choisit.

Do I pronounce the -t at the end of choisit?

No, the final -t is silent. It sounds exactly like the je (I) and tu (you) forms of this verb, which are spelled choisis but also have a silent final letter.

Why is the word différente placed after couleur?

In French, most adjectives go directly after the noun they describe, unlike in English. So instead of saying a "different color," French speakers say a "color different" (une couleur différente).

Why does différente have an -e at the end?

Adjectives in French must match the gender of the noun they describe. Because couleur is a feminine noun (which we can tell by the feminine article une before it), we add an -e to the masculine word différent to make it feminine.