Colours follow the noun and agree with it: um carro vermelho, uma casa vermelha. Those ending in -e or a consonant, like verde and azul, have one form for both genders and only change in the plural: verdes, azuis. Colours named after a thing, like cor-de-rosa and laranja, usually do not change at all.
Examples
- Tenho uma bicicleta vermelha.
- I have a red bike.
- Ela tem olhos verdes.
- She has green eyes.
- Duas camisolas azuis.
- Two blue jumpers.
The mistake to avoid
The plural of azul is azuis, not "azules": the -l becomes -is, as in hotel, hotéis.
Where this fits in
Colours, clothes & likes, Portuguese A1: Name colours and clothes, buy something in the right size, and say what you like and don't like.