It's similar to texture splatting; i have a set of layers (12 here), that each contain some conditions on the altitude and slope, an interpolation power, and a color. In the color table, for each texel i get the slope and altitude, and determine the layers affecting it. These layers are then blended together.
Don't forget that the generation of this color table is done once per planet, at construction time. So, i do not really care if there are 12 or 100 layers. In theory this allows me to make some planets with extremely varied terrain, although with "only" 12 layers, i think the results are starting to look good..
I can't decide which of the two textures is the best:
The first texture uses the layer which has the best weight, while the second one blends all the layers which have a weight > 0. The second one has smoother colors, but i'm not sure i really want this, as it'll make the textures less precise when appearing on the whole planet.