Rihanna has collaborated with MAC for new Viva Glam lipstick.

The 'Diamonds' singer has collaborated with the cosmetics company for the second time with the launch of a new lipstick and lipgloss duo.

Rihanna announced the news on Twitter as she urged fans to have a look at her latest beauty range with the popular beauty brand.

Alongside a campaign photo of her sporting bright green hair, she wrote: ''Check out my new @MACcosmetics #VivaGlam ad. All sales go to people affected by HIV/AIDS. Comin @ ya this September!!''

The limited edition range features two grey tinted frosted purple lip products, which echoes the 90s trend which Rihanna is particularly fond of.

Last year, the beautiful songstress released a bold red lipstick and matching tinted lip gloss with Viva Glam.

In the past, MAC have teamed up with Cyndi Lauper, Elton John, Nicki Minaj, Ricky Martin and Lady Gaga. Each celebrity then released a signature lipstick/lip gloss combo to raise money for the company's HIV and AIDS charity, MAC AIDS Fund.

The company donates 100 per cent of the purchase price to their cause, which supports men, women and children suffering from HIV and AIDS as well as providing financial aid to organizations working with impoverished regions across the globe.

Rihanna's collaboration with Viva Glam will be available from MAC stores and online from September.