I am in love with the Koigu KPPPM sock yarns. The colors are so varied and vibrant. You will be hard-pressed to decide which colorway to use, because they are all intricate and gorgeous! It knits up w/ a soft, beautiful texture. If it was edible, I would be gorging myself with it! I want to lie down and roll in it well, kidding, sort of!
The only comment I have though, is that I am lucky to live near Jimmy Beans so I could actually see the true colors. For instance, I got colorway 900X, and in the picture it looks mostly yellow. In real life there is a ton of contrast w/ light and dark blues that POP! emerald green and teal, dark rust. The picture in NO WAY does it justice. If I was deciding from a picture I would never have chosen it, but in reality, it was by far the prettiest. I'm not sure if that is true of other colorways, but the difference in picture/actual product is huge!
Still, it's hard to imagine being disappointed w/ any of these colorways. My family, friends and I are destined to be wearing lots of hand knit socks and hats!