Indigo Colour 

Indigo is a very dark blue and is like blue only intensified and with an internal focus. It is the  colour of inner awareness, profound insights and understanding. It is an excellent colour for inspiring ingenious ideas and therefore suited for inventors and others who need to be creative.
Indigo Crystals

Indigo Agate
Agate is an energy, harmony, and soothing stone. It helps strengthen the body's connection to the earth and ground emotions. It can give courage, energy, strength, and rid fears, and increase confidence. Agate also enhances creativity and stimulates the intellect. Agate is considered a stone that brings good luck.