It depends on what color you envison "denim" to be. . I mixed dark gray and dark cobalt to get a smoky blue that matched one of the book jackets in my book necklace. You can see the color of the book jacket in the photo of it, but the not the bead (see post called "stuff I was asked to show"). Unfortunately with color mixing it is hard to get the same color twice or mix a lot of color for a large project.