This method is dependant on the width of the blank. You need to create a single width blank so that 1 row unravelled from the blank will knit 1 round of your chosen sock pattern. It can be made with a single or double stranded blank as the pattern is the same all the way down the blank with no variation 2 socks knitted from a single stranded blank will match.
Dyeing the blank is incredibly easy, you won’t believe it until you knit it but all you have to do is divide the blank in half vertically then paint one half one colour and one half a different colour. Yes, that really is all you have to do!
If your calculations were a little out or your dyes bled along the centre line you may not get perfect single row stripes, there could be an overlap where a few stitches on the next round are worked in the previous colour. This is only to be expected. If you want perfect single row stripes you have to do it the hard way using 2 balls of yarn in different colours but where is the fun in that?
The principle is exactly the same as two colour narrow stripes but you need to use a double or triple width blank.