c# MySQL Auto Increment

Question

In Table A I have three fields. I want ID to be auto incremented without setting it as the primary key, But I want to make Color SN and Color PN the primary Key.
But the database will not allow me. The error says that AutoIncrement has to be an primary key. can someone assist me. My goal is to not have a duplicate Color SN or Color PN

Table A

ID

Color SN

Color PN