The only color of yarn that you will use a significant amount of would be the yellow. Other wise some small amount of scrap will probably allow you enough to make the accessories.

The base hat does not take a full skein of yarn. However with the big twist baby if you are making this for an adult you could go through about a half a skein.

The base hat pattern is just a generic I made for age ranges. To get a more precise fitting I always recommend to measure the head and measure the diameter of the hat while you are increasing. There are many free hat sizing charts on the internet to reference to make sure you have the right size.