The ornamental designs for the colostomy accessory, as shown and described.
FIG. 1 is a top plan view of a colostomy accessory of the present invention;
FIG. 2 is a bottom view thereof;
FIG. 3 is a side elevation thereof, the other side view being a mirror image thereof;
FIG. 4 is a rear elevation view thereof; and,
FIG. 5 is a perspective view thereof.
The broken lines shown in FIGS. 1 and 5 that are adjacent to the claimed portion of the design illustrate the bounds of the claim and form no part of the claimed design. The additional broken lines shown in FIGS. 1 and 3-5 illustrate portions of the colostomy accessory and form no part of the claimed design.