Why were the Kulzer shades HKA2.5 and HKA5 created?

HK shades

The HKA2.5 shade closes the gap between the most popular Vita shades, A2 and A3. There was a corresponding market demand for an intermediate shade. HKA5 is intended especially for use in treating cervical lesions in older patients. Previously, there was no corresponding reddish brown darker shade for this indication.