Chris Brown to L.A. City -- My House Graffiti Is Protected By the 1st Amendment!

Chris Brown is firing back at the City of L.A. -- claiming the gov. has NO RIGHT to force him to remove the graffiti art on the front of his L.A. home because it's protected by the 1st Amendment.

Brown just filed an appeal with the city -- telling officials the bill they're trying to stick him with for having an "unpermitted" mural on the front wall of his Hollywood Hills home is pure B.S..

According to the legal documents, obtained by TMZ, Brown claims the city is wrongly trying to nail him for having an illegal "sign" -- when the graffiti is art that "[enhances] the architectural and aesthetic features of the residential property."

Translation -- my artwork makes my house look dope, son!

Then Chris drops the constitutional bomb -- arguing, "The murals are a reflection of [my] aesthetic taste and a reflection of free speech and expression protected by the First Amendment to the United States Constitution."

Brown's case is now in the hands of the Dept. of Building and Safety's board of appeals -- and if they shut him down, he can bring the fight to L.A. County Superior Court.

In fact, there's a chance ... albeit a small chance ... that Brown's case could go all the way up to the Supreme Court if he's not willing to back down.