At the last update, I was applying the tape to the transparent film. Tonight I applied the coloured/colored film underneath to the sticky side.
The application in progress above. I used transparent candy wrappers for the deep violet and yellow parts, and coloured/colored cellophane from a stationery shop for the rest.
The nearly finished piece placed in situ against the window. When I finish the mirror side, I'll remove the paper backing, and apply the double sided adhesive film to stick them in their final position. I'd rather do them both at the same time just in case I want to make changes. Once I apply the double sided sticky, there's no way back. A bit like sex really. . .