Color Blocks 2 Mod, as its name suggests, not only allows you to add your own colors, using the cb2 file format but also enable you to make your decisions of whether to loadblocks/slabs/stairs (stairs require blocks) in these files or not. You can also remove colors by removing them in the cb2 files.
Colors have actual names (decided in cb2 files). All .cb2 files in the mods/colorblocks2/ directory (automatically created when starting (if it doesnt exist)) will be loaded. All the awesome features of the original colorblocks. Glowing and blast resistant blocks.