File a return as a resident for the state where you were physically domiciled (resided) while you worked.
If this state was Washington, then you file that state as a part year resident and report all income earned while living there in 2016, regardless of your "official changes".
If no money was earned while living in Colorado, then there is nothing to file or report. If money was earned in the first part of the year before the move then you file this return as a part year resident to report only the income earned here.
