The company has gradually been removing artificial colours and flavours from selected product lines since 2005.
It has redesigned the packs of Fruit Pastilles, Milkybar and Smarties with more prominent messages about the lack of artificial ingredients inside.
Nestle, which also manufactures Aero, After Eights and KitKat, has run full-page ads in The Guardian and The Times today, featuring the strapline "A Real Treat", to reassure parents that selected products will no longer contain artificial ingredients.
The UK confectionery market has been under heavy pressure from health lobbyists and the government to change the way it markets products to children.
Nestle has already removed blue Smarties from its Smarties range, while the brand has also been targeting mothers with its natural ingredients proposition; a move away from its previous strategy of directly attracting children with gimmicks such as the Milkybar Kid.
Last week, Ofcom claimed the government's new rules on advertising high in fat, salt and sugar foods to children are taking effect, accounting for a 27% drop in all food and drink advertising on TV since 2005.
Ofcom said while it is too early to make any firm conclusions from its findings, the indications were that its newly introduced restrictions were beginning to have an effect.