If you need to paint plaster apply color pigments. As a rule, these are powders, iron oxide pigments. The process takes place as follows, in pigs add pigment in a certain amount. Maximum is desirable to add a maximum of 10%. In this case, gypsum potine loses its properties.
If you add a couple of percent, the colors will be light. More than 5% percent, Nips in darker tones of color.
To evenly distribute the pigment among gypsum, it must be well re-animated. This is done by friction. They also say pereterat, tool or stone, pigment and gypsum pounded.
Rub and mix, and so on until the tone becomes uniform. Then you can knead the dough.