What type of color cards?

What type of color cards would people be looking for? My yarn comes in "mostly solids" and "semi solids", and then there are (well, will be once I set it up) a rather staggering number of multiple colored (2,3, possibly more in a skein, though I am not always fond of more colors-less can be more!). I know it would be nice to have the multiple color skeins in color cards available, but that adds up to a LOT of yarn.