Well since nobody else will take a shot at explaining color shift, I'll try. The paint used has a lot to do with the color shift effect. The pigment in the paint reflects light in such a way that the object appears to change colors depending on the angle of the light reflected from it. Pearlescent and gem shift colors are good examples of paints that have a color shift. Similar color shift effects can be made using layers of color. An example could be a base color screened by fine mesh then different color over the base color. Done properly and with the right colors the effect is, depending on the direction the object is viewed from, the color appears slightly different. Holographic foil under transparent paint can produce color shift as can holographic glitter. Color shift is really a lot more complex than this explanation... I looked everywhere for a scientist to explain it but I couldn't find one for love nor money, so I had to settle for this one.