I think Its also against the rule to copy others things, Like signature. Its a copy write Issue, No doubt its unethical but its also Illegal.
What 'rule' are you referring to? Illegal in what jurisdiction? Which IP right has been infringed and who owns it? Which combination/proportion of orange/blue background are allowed and which are 'illegal'?
Since you have 'no doubt' you'll have no difficulty answering those questions.
More can be explained by Marco or Bit-x itself that its Illegal or Not?
Marco and Bit-x can express their opinion, but none of them have power to decide what's legal and what's not.