For my design I choose Mint and Lavender Mint associates with freshness, energy, fresh breath and it's classic for oral hygiene products Lavender - the scent of relaxation, spa, freshness and comfort
Both of these colours are complementary and work well when paired. Colour of brushes are very bright, but not too much to annoying in the morning when you have not yet woken up and in the evening when you are already at rest.