What is a difference between 100 (Black) and 110 (Special Black)?

100 (Black) is a dark black with a slightly bluish tint that goes well with cool grays whereas 110 (Special Black) is a clean black that works well with neutral tones. It is also worth noting that the amount of dye in 100 (Black) is slightly higher. The difference is small however so please use these shades according to your preference.