After chewing for about 30 seconds, the old plate will turn blue and the new one will turn red. Without Erythrosine (E127). 12 Developer tabletsCuraprox plate developer inserts are valuable aids, with guaranteed success. They reveal plaque in the mouth, clearly showing where extra brushing is needed. As an added bonus, plaque is motivating, as the best reward is seeing plaque disappear. - Bicolor system: the old and structured plate appears in blue and the newly formed plate in red. - Erythrosine free (E127) - A pleasant fruity flavor