Actually there is no pink color. Of course, we can see it, but it's just a game of imagination.
The fact that it is a combination of red pink and purple color, which are disposed on opposite sides of the rainbow.
Pink does not exist because you can not bend the colors of the rainbow so that the purple and red mixed.
This color is an illusion of our vision and brain. If you look at the pink thing, you really do not see the pink wavelength of light. It just seems rosy from the fact that some of the light waves are reflected, while the other waves inhibits pigment and they are absorbed.
It turns out that the pink color is not transmitting. People see the pink just because the brain produces light reflected from it.
The scientific name of pink - green negative, because it is a residual from the influence of white at the moment when we remove the green.