author: Will Earley
The title gives the first two clues, though the information can be gleamed from the pictures as well. 'When you wish upon a thousand stars' is a reference to the fact that, according to legend, by folding a thousand origami cranes you are granted one wish. 'Ciphers' hints that there is a code to break.
Inspecting the images, the right one may be recognised as the net of a crane. If you don't recognise the net, however, then the lines may hint that folding is the appropriate step. The colours of the rainbow, ROYGBIV, give the order of folds (or an origami tutorial for the crane can be followed). There are also some letters on the image, but it is not obvious how they come together. Folding indeed results in a crane, and brings the letters together around the base. Reading these off gives uxujfsl.
The left net can also be folded, though may not be immediately recognised. Red signals to cut, so there are two pieces that fit together. Folding each piece brings the yellow and green patches together, and directs how to arrange the two pieces to complete the final (green and yellow) folds, resulting in a shuriken. The final shuriken brings together the correct pairs of letters, giving the cipher.
Reversing the cipher on the ciphertext gives the final answer, paperfu.