How to color plastic?

There are two ways of coloring plastic: 1. That is, the masterbatch and plastic particles mixed evenly, so that the injection or extrusion stage in the processing of molding melt together, so that the processing of the plastic parts as a whole from the inside out are a color. 2. to the processing of the plastic parts of the finished spraying color. This requires certain equipment and conditions, individuals are not easy to realize at home.