Wall Slits don't fit with the wall

Request from Discord: "The wall slits stamp is hard to use, because the outside edge is so much darker than the inside. If you place it as is, the outside looks too dark to fit with the wall (left. If you brighten it, the inside is way to bright to fit with the wall (Middle). The only way I can find to slightly remedy this is by lowering the opacity slightly (right).

What if the outside edges were painted a certain color instead of just dark?"