Pink and green is the new black and yellow. In a baffling and potentially dangerous move, that is the new colour scheme the New Delhi Municipal Council is applying to the road dividers and roadside kerbs in its jurisdiction. “It’s kind of an aesthetic initiative,” Anant Kumar, the NDMC chief engineer told the Press Trust of India.

These new colours are already visible in several parts of central Delhi, such as Kasturba Gandhi Marg, Rajiv Chowk and Ferozshah Road. The NDMC plans to finish the repainting within two weeks.

The problem is that the standard colour scheme of black and yellow isn't used because it looks pretty: it serves an important safety function. When set against each other, these colours present very sharp contrasts, alerting drivers to potential obstacles.

These colour combinations have been evolved after decades of international debates and conventions, starting with the first international Convention on Road and Automobile Traffic in 1909. This eventually resulted in the Conventions on Road Traffic and on Roads Signs and Signals of 1968.

Delhi's new pink and green road elements won't be especially visible at night, and will be difficult for colour-blind people to recognise. Already, a flood of complaints from road users and from the city police has increased the cost of the beautification drive: the NDMC has had to affix reflectors to the dividers and kerbs to make them easier to spot.

Some of critics complained that road dividers and kerbs will be harder to notice. Others are wondering how the authorities actually came up with the new colouring scheme.