At night the sculpture will be illuminated internally, which is good, as back lit glass looks gorgeous. But if you think of a church stained glass window, the colours don't show up from the outside, so I have had to come up with a system that works during the day when the glass is not illuminated.
I have tested layering up different types of translucent white glass with the coloured and clear glass so some colour and the etched images are clear when not back lit...
It's not straightforward, as some of the colours are much more opaque than others (e.g. the green above), and some of the white glass changes the hue of the colour. For example, opal glass is wonderful on reds/yellows, but makes blue glass appear brown when backlit!
In the finished sculpture, the etched glass circles will form a coloured pattern based on a section of the Cosmic Microwave Background