This hat is made from medium bulky weight wool yarn alternating with finer spun silk accent stripes.  It's a standard round cap length designed to cover most or all of the ears. The greens and dark rust are all Corriedale wool.  The teal blue stripes are Icelandic wool.  The lavender and gold stripes are tussah silk.  Tussah silk is also known as 'wild silk' (tussah means wild) and the silk worms, which are actually caterpillars, not worms, are allowed to leave the cocoon before the silk is gathered, unlike farmed bombyx silk where the cocoons are dropped in boiling water to kill the caterpillar inside before harvesting.  For this reason I use only tussah silk. Tussah silk is often a golden color because the caterpillars eat various leaves containing tannin.  So the gold colored silk in this hat is the natural color of the silk.