Please try to use the Edit button next to the Color Appearance text box and then under the Main View tab you can set your conditions.
If you want to use an equal condition use the field called "Field Value". If your field is numeric you can use the previous field or you can specify an interval type condition (greater than and less than) using the field "Field Value Range". For more details please check our documentation.
If you've tried that already please provide your QWP and SP version as well as the web part and list template and the scenario you want to accomplish.