Color is important to me when I choose fiber. It's the first thing that catches my eye. But what color yarn will I get? The colors turn out somewhat muted, because they blend as they're spun together. The fiber in the first picture is very bright, but once it's spun it's not quite as bright, as you can see in the second picture. If you ply the yarn, the method of plying the yarn makes a difference too. With variegated color as shown in the photos, the Navajo plying method preserves the color gradation - a transition from one color to the next. Navajo plying creates a three-ply yarn, as in the third picture. Variegated fiber plied as a two-ply yarn creates an effect with a blend of contrasting complementary colors. Washing changes the color of the yarn too, because quite a bit of dye can come out.
Though it's not obvious, perhaps you can see in the photos the subtle change in color from the original fiber to the spun yarn and then the Navajo-plied yarn (the final product).
For more on the Navajo plying method, check out the video on http://www.joyofhandspinning.com/spin-navajo-ply.shtml