The different color fields are knit with a special “code”. That means: the short rows are shortened in various intervals. Those intervals are combined in a code. The code is developped before starting to knit and will never change until you finish the picture.

The matchsack has a lining where you can store the different packages for yarn

This is no pattern but a technique. If you want to learn it, search after “Strickrausch”, where you can book live or online-courses or go to Heidrun’s Ravelry Swing-Knitting-Site where you can buy tutorials.