The square uses 3 colors.

The third color is added in the 4th round.

Do not cut the unused color.

The color change is worked as follows:
With working color yo, insert hook in the st, yo pull up a loop, yo, pull through 2 loops, drop working color, yo with next color and
pull through last two loops.

The number following CA (Color A)or CB (Color B) refers to
the number of stitches in that color, 1 stitch in each stitch unless otherwise specified. (Example CA5dc in next st means all 5 sts are made with CA in the next st).

The yardage mentioned is for one square.