DECREASES
(…)
Round 1:
K2 with color A, k2 with color B, k1
with color A, ssk with color A,*k1 with color B,
knit 10 sts in stripe pattern, k1 with color B,
k2tog with color A, k1 with color A, k2 with
color B, k1 with color A, ssk with color A*. 
Work from * to * a total of 4 times, k1 with color B, knit 10 sts in
stripe pattern, k1 with color B,
k2tog with color A (the last stitch from round
1 and the first stitch from round 2).