The Tiffen 6 x 6" 3 Plum Soft-Edge Graduated Filter helps to specifically add a warm, pale purple coloration to skies and other bright areas of an image while allowing a portion of the image to remain neutrally colored. The filter's coloring is densest at the edge and tapers to clear by the middle, with a soft-edged transition between the density and clear areas. The 3 color density provides more plum coloration than the 2 density filter.