Instead of a border, I added a reversed row of fans on the foundation chain (just the second row of each fan, using the chain row as the V to work it in).

In my gauge, each color repeat of the sweet roll was good for two rows of 12 fans each. To get the perfect alignment, I cut off the extra at the end of each pair of rows (and then wove in all those resulting ends…)

The total amount of yarn was closer to 3 skeins than 3.5, but because I wanted the colors aligned, I lost a lot to the color changes.