Making fake bruises for plays and other stage performances can be as easy as drawing on yourself with markers. Using certain colours and the right process can make marker bruises quick and convincing. The bruise artist simply needs to make sure to use washable, water-based markers--or else the bruises may last as long as real ones.
Colour the skin with a light lavender marker. Make sure the shape is irregular, and smudge the edges of the mark with a tissue or finger.
Add a line of olive green around the bottom edge and smudge it.
Draw over the green with the lavender and smudge it.
Add a line of baby blue to the top of the bruise and smudge it.
Add a couple of dots of dark purple to the middle of the bruise and smudge it. Cover it with lavender marker and blend with a finger.
Add a little light yellow-brown right next to the olive area; smudge it and cover it with lavender.
If the bruise seems too dark or contrasting, dab at it with a slightly moist tissue.