With a fullcolor solid state laser, (at least) three different laser modules are used together. White light as well as mixed colors are generated by the additive color mixture of red, green and blue (like e.g. the TV set). Color shades are produced with the partial switch-off or the dimming of single colors, which is so called "analogue modulation".
To increase output power or to create a larger or more vivid color range, it is possible to mix even more than three colors (e.g. we do so in most of our RTI NANO systems). It needs some knowledge to operate such systems properly.
The wavelengths of the individual laser modules define the color. That's why it is very important to have the "right" red and the "right" blue to get good visibility with a good color spectrum at the same time.