An embroidery data creation apparatus includes a thread color relation value storage device that stores a color relation value that corresponds to a color, for each embroidery thread which is used in an embroidery data, a preview image creation device that creates a preview image, a preview display device that displays the preview image created, a reference region specification device that specifies as a color modification reference region at least one region in the preview image, a thread color selection device that selects a thread color to be used for the reference region specified, an image data color modification device that modifies the color of the image data based on the color relation value corresponding to a color of a reference image region and the color relation values corresponding to the thread color selected, and an embroidery data creation device that creates the embroidery data from color-modified image data obtained.