The problem with multi-colored yarn.

Exhibit A

Exhibit B

Why do some multi-colored yarns look fantastic after knitting and some look like color barf? Its hard to tell by just looking at the ball. Exhibit A: multi-colored yarn by Malabrigo Yarn that I used to knit a herringbone stitch scarf (aka My So-Called Scarf). This I like. Exhibit B: yarn by Three Sheep Yarn striped with solid purple that looks like barf. Ok maybe its not that bad, but I'm less than happy with it. And its supposed to be a gift, so that make me madder at it. Nonetheless, I was really attracted to the yarn ball in the store.
One indicator might be the length of each color. For example in Exhibit A I got a couple stitches in each color before it changed. With the Afghan yarn, sometimes I get just one stitch and then its another color. Maybe I'm just unhappy with the color palette. How do other people evaluate multi-colored yarns before buying them?