-----It should be Ok anything else would be posible.even red, black...??? even the upper side of the wind would be similar than the lower one, same scheme.
Otherwise, fabric material colour rather than silver colour, elsewhere in those years the most typical was a mixtute between fabric varnish with pigment of silver......."clear dope"
This particular aircraft came in german hands in the begening of the war and fore this reason I think it was not neccessary to re-paint..in my iopinion remain in the original colour, otherwords it was not a problem if the aircraft was red.
It is worth to check other Stampe to know the factorie colours..
There is a mistake in the drawing, mind that it is "ESPAÑA" not Espa"N"a..
this letter is fundamental in the spanish lenguage.
I have the oportunity to make a joke "un-politacally correct".(as me)..imagine if you write AÑO...without "Ñ"....the result is "ANO".........jo, jo, jo, joooooooooooo