I think those are actually better if are designing from scratch or for major modifications of templates. I think quick reference and a big overview is the main reason for this. If one really doesn’t know what color you want, a big overview might help — then after you pick a color out, use the color combo sites you have to generate colors. It’s kind of like going into a paint shop and looking at color swashes on the shelves, you have every available color in front of you, you just pick a main color you like — then you look at shades it has. it’s useful if you really don’t have a specific color in mind.

is it easy to switch and what’s the effect? not sure… i just did it the way it as it seemed logical to me from left to right (dark to light). interesting question though.