Color Changing Cotton yarn is now available as a 6-ply. This slightly thicker cousin of the 4-ply yarn is available in 100 gr skeins in my Etsy shop,
Wolle's Yarn Creations.
This 6-ply yarn has appr. 320 yds/100 gr and is a sport/DK weight. With a US size 6 needle, projects with this yarn knit up quickly... So far these colorways are available (more coming soon):
ORANGE CHOCOLATE I and II

AQUAFROG I and II

PURPLE SALMON I and II

GOLDEN PURPLE I and II