The blue sweets were first introduced in 1989 - and discontinued in 2006 as part of a drive to remove artificial ingredients in children's food.
Makers Nestle say the new colouring comes from a seaweed called spirulina.
The firm says the other seven colours in the packs also have no artificial colours and flavourings.
What are these?
Most Popular Now | 48,771 people are reading stories on the site right now.";