Abstract: An embroidery sewing machine for producing an embroidery pattern in an embroidery area on a work sheet by filling the embroidery area with stitches, including a stitch-forming device having one or more sewing needles each of which carries a needle thread and reciprocates in an axial direction thereof, and a needle-thread catcher which cooperates with the sewing needle to form the stitches into the work sheet; a displacing device which displaces the stitch-forming device and the work sheet relative to each other; and a control device which controls the stitch-forming device and the displacing device so that a predetermined portion of the embroidery area is filled with mixed stitches formed of a plurality of color-different needle threads such that the predetermined portion is seen to have a hue of color different from a hue of color of each of the color-different needle threads.