Colors - Los Colores

Agreement

Since colors are adjectives (they describe what the noun is like), they must agree in number and gender with the nouns to which they are attached. Colors that end in vowels will end in 'a' to agree with feminine nouns or 'o' to agree with masculine nouns. If a color ends in a consonant, such as 'azul', it doesn't change. To pluralize a color that ends in a vowel, simply add an 's'. If the color ends in a consonant, add 'es'. For example:

el gato negro - the black cat
los gatos negros - the black cats
la pared azul - the blue wall
las paredes azules - the blue walls

Double Colors
Agreement with the noun is slightly different when the name of the color includes two adjectives instead of just one, as in 'azul claro' (light blue). The second adjective, in this case, 'claro', is the one that must agree with the noun. The first adjective, blue, does not change. For example:

la casa azul clara - the light blue house
las casas azul claras - the light blue houses