We made the seam black on advise of Smith: Elliot

Kookaburra changed the colour of the seam from green-white to black to make it more visible on the advise of Steve Smith, who led Australia to a historic victory inside three days in the only pink ball Test.
Kookaburra Group MD Brett Elliot, who is here on the eve of India's first ever day/night cricket match, said black seam would lend a massive boost to the visibility.
"We have changed the colour of the seam since the Adelaide Test. After the Adelaide Test, where the ball had green and white seam, we spoke to (Australian captain) Steve Smith and he wanted a more visible seam. So, we introduced the black seam," Elliot said.

"The visibility is massive especially when it is played under lights. We have designed the seam to provide support to the spinners as well."
With their eyes firmly set on hosting the proposed day/night Test against New Zealand, the Cricket Association of Bengal four-day Super League final between Mohun Bagan and Bhowanipore Club will be played under lights with pink kookaburra ball from tomorrow.
The only pink ball Test between Australia and New Zealand at the Adelaide Oval in November last year had finished inside three days with seamers accounting for 29 wickets.

"For most players the visibility is better. Only one player thought the ball looked bigger than normal. Players are generally conservative. Before the Adelaide Test, they were not too excited but after that they said it was good."

The Aussie further said they are developing pink ball at their Meerut-based centre to make it better suited to the Indian conditions.
In the spin-friendly subcontinent conditions deterioration would be massive concern but Elliot said the it is slower here in case of the pink ball.