As requested - the pattern:
4mm needles (or maybe 5mm - or 6mm - whatever you have and are comfortable with)...
Random balls of yarn - or remnants.
Cast on as many stitches as you like - say 20 or 25... with some yarn or other
Garter stitch (ie, every row knit) with colour A until you get bored. Join on another yarn,and chop off colour A and garter stitch that until you're bored. Repeat until it's long enough.
To stop the yarn possibly coming apart, tie a knot in the ends of the 2 yarns, and leave dangling.
If you want to get fancy, you can do other stitches - but the size of the scarf and the different colours makes it a bit moot.
There you go! Easy! Perfect project for the beginner knitter.