Bill Nguyen, the serial entrepreneur who sold his last company to Apple Inc in 2009, is launching a new cellphone-based social network which aims to challenge Facebook's dominance in social communications beyond the personal computer.

Color is a free smartphone-based application on iPhones and Android devices which lets people in close proximity capture and share their photos, videos and text simultaneously to multiple phones in real time.

With photos and video-sharing being one of the most popular activities on Facebook, Color's founders hope the always-on mobile nature of Color will create a different kind of 'post-PC' social network. Nguyen said social networks and apps were moving users away for PC-based Web many users were initially familiar with.

This transition to post-PC world is going to be a huge fundamental shift, said Nguyen. We're sharing more and more information in real-time.

Nguyen, who sold online music start-up Lala to Apple for a reported $80 million, worked with the iPhone maker for just under a year.

In September he raised $14 million in seed funding from Bain Capital Ventures and Silicon Valley Bank. One of Silicon Valley's biggest venture funds Sequoia Capital came on board just before launch with $25 million and another $2 million from Silicon Valley Bank.

Color is a free service with no user names or passwords but Nguyen and his team are hoping to be able to generate revenue through advertising and location-based marketing services.

People are starting to realize with devices like the iPhone that you can do things on a social network you could never do before on a PC, said Bain Capital Ventures Mike Krupka, who had previously backed Nguyen with Lala.

The company said it will be using the latest round of funding to accelerate its development and infrastructure build-out to analyze large volume location information.

Color recently hired DJ Patil, the chief scientist of business social network LinkedIn. Patil joined Color as its new chief data officer to help analyze the vast amount of data it anticipates as users of the network move from location to location.

Nguyen had previously founded companies like Seven in 2001,

and Onebox before that which he sold in 2001 for $850 million to Phone.com. Color will be his eighth start-up.

(Reporting by Yinka Adegoke; editing by Carol Bishopric)