Pinking shears are scissors that cut with a sawtooth edge. They are used to prevent fabric from raveling.
The word pinking has nothing to do with the color pink. The word comes from a little-used English verb that means to poke a hole in. It referred to a process of ornamentation. One piece of fabric or leather would be slit or perforated to allow another color or texture to show through. Some fancy cowboy boots are made that way.
Later, the word pinking came to apply to the cutting of a zigzag design. That’s the sense it has now when we talk about pinking shears.