Colored waves

hi all, i really love this wavesimulator, and i use it vvvery often for many types of fx (just for example used for displace map for other shaders ot something like this). But this time i need a colored wave simulator. For example i have many circles that makes waves, and every circle is colored (one is red, one is green and so on).
but how can i do? if i understood well the shader use the luminosity of texture for calculating the wave propagation, i tried with all the texture formats, but always the result is greyscale, and if i use the saturation in the emitter it seems to stop producing waves. difficult to explain, hope you understand my problem and what i need to do
thx ;)