Concordancia de adjetivos
 

I know of course that in Spanish, adjectives have to agree with the noun. Obviously, this goes for colour adjectives, too. But what happens if I want to use oscuro or claro with the colour adjective? Is it "zapatos azules claros"?
I'd much appreciate it someone could clarify this.

camisas azules (azul is an adjective)

camisas azul claro (azul is a noun, claro is an adjective which modifies that noun; equivalent to camisas de color azul claro -all the shirts are of the same slightly light blue-)

camisas de azules claros suggests differently coloured shirts, all in a shade of blues (on the lighter side)

camisas azules claras is possible in the real world with (about) the meaning camisas azul claro, but it suggests that the speaker is naming two different attributes of those shirts as in camisas azules grandes.

Remember, in Spanish, when you use a noun as an adjective, the noun doesn't agree with the noun:

camisas azul claro
palabras clave (keywords)
niños problema (~troubled children)

Dear Alec,
that's sounds very clear and convincing. Muchas gracias
el faro