Using the same yarn for both C1 and C2.
I had 2 hanks of the same colorway, and I knew the color sequence- there are 7 colors. I decided what colors I wanted to pair, and to use a whole section of the first color I had to cut off a little bit of yarn from one hank. For the other one I had to cut off several sections to get the one I needed. Also, I use one skein in the opposite direction- from the other end.

How to Purl Backwards