Last December I did some leadlight panels (stained glass in some circles) for a tall, thin window in our pantry. I was really happy with the results, except for one thing: I felt I had chosen badly when selecting the colour for the wings of the fairy in the bottom panel (left side, above). I felt that they were too dark. But that meant cutting into the 'finished' panel, removing the dark pieces, cutting new ones and then reassembling everything. It could all go horribly wrong.
This afternoon I bit the bullet.
And am happy with the result.