Mary-Kate and Ashley Olsen want to launch new haircare and cosmetic products through their Elizabeth and James line.

The twin designers are ''excited'' about what the future holds for their brand, and will be looking to expand further ''when the time is right''.

Mary-Kate said: ''We grow our brands organically - taking the time to find the right opportunities and identify niches in the market.

''There is a lot of opportunity in colour [cosmetics] and hair that we are excited to explore further when the time is right.''

For now, the sisters are focused on the UK launch of their Elizabeth and James Nirvana fragrances - which will feature the new Nirvana Amethyst and Nirvana French Grey alongside the original Nirvana White and Nirvana Black, and the popular Nirvana Rose and Nirvana Bourbon scents - and admit working in the beauty industry is very different to their fashion ventures.

Ashley told Harper's Bazaar UK online: ''We're excited to be introducing Elizabeth and James Nirvana to a global audience and new international markets.

''Lead times are longer in beauty because the product is not seasonal like it is in fashion.

For their fragrance collection, the 31-year-old sisters were keen to keep things as ''pure'' as possible.

Ashley said: ''For each Nirvana fragrance, we challenged the perfumers to keep the scent simple and true to the raw notes.''

Mary-Kate added: ''Ashley and I are drawn to scents that are pure. Single notes can be very nostalgic.''

The sisters designed the packaging - textured glass bottles with architectural lines with a different colour for each fragrance - themselves and wanted it to be something ''beautiful'' in its own right.

Mary-Kate explained: ''The bottle's texture is inspired by a vintage object.

''We wanted something that would remain beautiful on its own.''