I added sections without shaping to the middle of the scarf. As a result, I ran out of Brillino at the very, very, very end of the scarf. Because the Brillino tempered the very bright orange so much, finishing with just the Seta Suri was not an option, so I used a very small amount of yarn from a second ball. (Ripping back half the scarf was also not an option.)

One ball of each yarn is plenty to knit the scarf as written.