Learn Portuguese (Portugal): O carro é vermelho.

In Portuguese, there are two verbs for "to be": ser (used for permanent or defining traits) and estar (used for temporary states). A car's color is considered a permanent characteristic, so we use é, which comes from the verb ser.

Would the word for "red" change if we were talking about a feminine object?

Yes. Adjectives (describing words) must match the gender of the noun they describe. Since carro is a masculine noun, we use the masculine form vermelho. If we were talking about a feminine noun, like a bicycle (a bicicleta), the color would change to vermelha.

How is the double "r" in carro pronounced in Portugal?

In European Portuguese, a double "r" is pronounced from the back of the throat, sounding quite similar to a raspy English "h" or a French "r". This is very different from a single "r" in the middle of a word, which is made with a quick tap of the tongue against the roof of the mouth.