Sony Worldwide boss Shuhei Yoshida has explained one of the ways the light-bar on DualShock 4 will work by using the Killzone: Shadow Fall demonstration show during the PS4 event as an example.
Speaking with Edge, Yoshida reiterated that the light-bar would help players identify their controller, over say a co-op partner's, by the color of the LED light.
He also said the light-bare doesn't "require the camera to function." However, with games such as Killzone: Shadow Fall, the light-bar could take on a "dual or triple" role.
"Game designers could use it for some effect," said Yoshida. "Like when [players are] losing HP, the color could change from green to red. Like in the Killzone demo, if you were watching Steven playing, [that game] has that function already.
"People were watching the main screen, but Steven was facing the audience, showing how the light bar color changes as he was hit by the enemy; as he lost hit points the color was changing from green to red. And when he used the health replenishment, it went back to green."
Yoshida said the idea for the LED bar came from Richared Marks’ ream, which helped develop PS Move.
PS4 and its DualShock 4 controller is expected this holiday season.