So a couple of months ago I made a sweater using this pattern
as written (which is for a newborn sized sweater) using KnitPicks Shine Sport in "River" with cream stripes.
I've made this sweater again using the same pattern and yarn (only this time I used cream as the main color and used the "River" colorway for the stripes). The only change I made was that I went up two needle sizes ... I used a US 6 for the main body and a US 4 for the ribbing. My goal was to create a slightly larger size, and overall I think it worked out pretty well. This sweater is more of a 6 month size I would say.