gray in the case of lies doesn't mean gray areas, a grey lie when identifying lies actually means that the lie benefits both parties without causing harm to either side. A white lie is a lie that benefits the other party at the cost of the liar, a black lie only helps the liar at the cost of the other party, and a red lie hurts both the liar and the other party.

I would say that type of system could only be objective, while the intent does matter as well, I believe a lie that harms the other side, even when you meant otherwise would be either a red or a black lie, since it harms the other it can't be gray or white.