I finished folding an additional 8 cranes last night to complete the first set of 40, then I strung them and hung them up.
The string has the same color gradient as the rainbow: red, orange, yellow, green, blue, indigo and violet. There are a few shades of each color, 20 shades total, which makes the rainbow gradient smoother. There are 2 cranes for each shade.
Over the past weekend, I folded cranes while listening to old episodes of the British sitcom 'Allo 'Allo! and I estimate that each crane takes about 5 minutes to fold, though I've not been timing myself.
I'm going to be working on homework today to get a head start on the term, which means that I won't be folding nearly as many cranes as I have over the past couple days.