The Centre has formulated a new list classifying 733 districts across the country as 130 red zones, 284 orange zones and 319 green zones to implement its Covid-19 containment strategy and enforce the third phase of the lockdown starting on May 4.The Centre has formulated a new list classifying 733 districts across the country as 130 red zones, 284 orange zones and 319 green zones to implement its Covid-19 containment strategy and enforce the third phase of the lockdown starting on May 4.