Does every color name follow a different conjugation pattern with an adjoining noun? Like, Grünen Röcke, Rotes Haus. Schwarze Auto. I'm unable to understand. Please help.
Colors change endings just like any other adjective. Below is something I wrote about a week ago in response to a question along the same lines:
There are two types of determiners. der-words (der, dieser, welcher, etc) change endings like der. ein-words (ein/kein, mein, etc) follow the pattern of ein. A noun phrase can start with a der-word, ein-word, or neither.
Rule of thumb: whenever there is an adjective, something in the noun phrase must have the der-word (strong) ending. If the determiner doesn't do it, the adjective has to.
If there is a der-word, that takes care of it, so the adjective has a weak ending -e or-en. -e is used in the singular nominative for all three genders and in the accusative singular for feminine and neuter. -en is used everywhere else.
ein-words have the same endings as der-words except in the masculine and neuter singular nominative and neuter singular accusative. The determiner has no ending in these three situations, so the adjective must have the der-word ending. (der alte Mann/ein alter Mann, das kleine Kind/ein kleines Kind). Everywhere else the adjective has the same ending as when used with a der-word.
If there's no determiner, the adjective has to have the der-word ending. (A text book I have says this combination rarely comes up in the genitive case in modern German and doesn't bother list the adjective endings. You would still need to know this for the other three cases.)