no, laranja is referring to the color orange. Some words, when they refer to colors - rosa (pink) is another one - are always singular.
Well, "laranja" and "rosa" are just short names for "cor de laranja" and "cor de rosa" (lit. "color of orange" and "color of rose") which are the real colors' names. So in that sense, the answer to your question is yes. When you say "sapatos laranja/rosa" you're actually saying "shoes with the same color as an orange/rose".
(of course, we are aware that not all roses are pink, which means that, ironically, some roses have the "color of a rose" and some not :P)
Thank you very much for your clear explanation. I wasn't able to find anything about "Portuguese invariable adjectives" online or in my Portuguese grammar books, but that's probably because these words are not technically invariable adjectives.
Yes, it's the same in French. Orange and rose stay invariable, to avoid confusion with the nouns with the same name.
In Portuguese, every time a color is also a noun, it is invariable. For example: cinza (gray/dust).
Yes, I'll give you a few examples:
red - vermelho/vermelha/vermelhos/vermelhas
green - verde/verdes
blue - azul/azuis
yellow - amarelo/amarela/amarelos/amarelas
So im brazilian and can be laranjas or laranja cuz the adjective may or may not agree with the object, and the best option is laranjas cuz laranja can mean the sapatos is made of oranges
Quando nomes de cores também são substantivos, eles não devem ser pluralizados.
"Sapatos laranjas" é incorreto em português.