Indigo Luster is a very dark violet black that is full of silver and can produce many colors both encased in clear and unencased.  While encasing this color in clear, have your propane on the torch turned up a little extra compared to your normal working flame.  This will bring metals to the surface and allows you to trap metallic blues, turquoise, creams, greens, and purples in the form of streaks and veils.  Depending on how much the color is blown or stretched thin, you can keep the encased metallic shine very reflective.  When the color is thinned, it will transmit a brownish purple tint. 

When Indigo Luster is unencased you will see color shifting as a result of normal working conditions.  Your dark violet glass will change to a hazy blue, then to turquoise, and end up around a creamy yellow green that can be reduced to a gold green metallic color.  Light reduction will highlight the current color you see with metallic shine or wispy variations of other colors close to it in the shifting sequence.  Intense spot heating will burn through the metals on the surface of the color to get back to the base color.