Translated from: The Granny Spiral by Patty Crochète
Abbreviations (US terms):
ch = chain stitch
dc = double crochet
tr = treble crochet
sl st = slip stitch
You'll need 4 colours of the same weight yarn.
* All stitches are worked in the top of each stitch of the previous row, not between the stitches, unless otherwise specified. You could do an interesting variation with using back loops only, or both loops for a smooth finish.
* I don't recommend using the Magic Circle to start this square, as it makes the square rows twist a bit.
* As you stop working with each yarn, pull up a nice big loop or use stitch markers so you don't accidentally undo all your lovely work
* To stop your yarns getting tangled, at the end of each sequence of four colours turn your work ANTI CLOCKWISE to get back to the first colour. If you keep turning the same direction, you'll get an awful mess.