The focus of this design is the glass square in the center of the field.
For this I have chosen a piece of Dichroic. Dichroic is a coated glass that changes color depending on the viewing angle. This glass is quite expensive and is therefore rarely seen in the Stained Glass design. It's a pity actually, because calculated down to the small amount needed ( as in this piece ), the glass is not that expensive. Often Dichroic glass is offered in connection with Fusing glass.
You should definitely try Dichroic, I like to work with it very much - in small pieces, as accents.