To say "there is no right" is self-defeating, since if that statement is right, then it is wrong. If it is right, then there is at least one example of something that is right, and that is what the statement denies. So it can't be right.
To say "there is no wrong," is likewise self-defeating, although in a somewhat more subtle way. The words "right" and "wrong" possess their meaning as part of a pair, like inside/outside, or top/bottom. To deny either half of the pair is to deny the other, and that is -- again -- to say that there is no right. Which, as I believe I've already shown, is wrong.
So what are perspective and opinion.
Perspective is very important in determining what propositions mean. But once a clear meaning is assigned, there can be a right or a wrong in the matter.
Maybe we can never be certain which is which. Which is wrong and which is right in certain matters. That would leave it a matter of opinion. It wouldn't be the case that there wasn't any wrong/right, only that we'd be left uncertain.