Most of the paintings that I do are "full color" which means that I use all of the colors on my palette.
My palette consists of 2 reds, 4 blues, 3 yellows and some earth colors such as Raw Sienna, Burnt Sienna and Burnt Umber. Occasionally I will add an extra color depending on the subject matter. Using my entire palette of colors enables me to make subtle changes of value, temperature and intensity while painting.
It is important to know and understand the different types of pigment available in transparent watercolor paints. There are three different types:
1. earth colors
Earth colors are pigments made from clay. For example, Burnt Sienna is a reddish brown color made from clay that has been taken from mines in Sienna, Italy for hundreds of years.
Burnt Sienna contains a large proportion of anhydrous iron oxide. It is made by heating raw sienna, which dehydrates the iron oxide, changing it partially to haematite, giving it that rich reddish-brown colour.
However, the mines are running out of this "dirt", forcing paint manufacturers to develop this color with different materials. These materials can contain impurities which will affect the pigment in the painting process.
For that reason, I prefer to only use pigments that are made from natural iron oxide. This information is found on the back of the paint tube.
Dyes are made from chemicals that are heated to different temperatures to obtain a variety of colors.
Metals like Cadmium and Cobalt, are mixed with additives and heated to different temperatures, then ground into pigments.
In watercolor painting, these three different types of pigments do not "like" each other. In other words, trying to mix them to obtain a smooth, even color will not produce the effect you are trying to achieve. If you want a smooth even blending of colors, I recommend that you use pigments in the same group. If you want the colors to separate to create an interesting texture, then use pigments from the different groups.
For my painting, I want the colors to separate to create textures that suggest the subject matter. In this example below I used phthalocyanine green–a dye, and cadmium yellow light–a metal, and some burnt sienna –an earth color.