A color vector cannot be used. This leaves the color map to give the media a color. Because it uses a scattering model, the colors filtered by the media will be the complimentary color of the media. This is different than a filtering model where the light is filtered both ways through an object. To do this, an absorbing media needs to be used.
Absorption can filter light.
It is needed to balance the light in a scattering media. Because it must use the compliment of the color that the scattering uses, we must place it in a new media that uses the same pattern as the scattering, yet the opposite color. We create a simple sphere. The sphere has a pigment that is completely clear. We render this and see the middle of the particles that have been scattered back to the camera where we have specified the colors in the color map.