 It criticised the government for not identifying that Carillion was financially struggling long before its January 2018 collapse, saying its "traffic light" system of warnings (rating suppliers as green, amber, red, plus black for 'High Risk' status) was "too slow and clunky".Carillion had been downgraded to red following its July 2017 profit warning; when officials recommended a provisional black rating in November 2017, Carillion bosses persuaded them not to.Like the Business and the Work and Pensions Select Committees, the PAC called for a Cabinet Office review of the roles of crown representatives after they failed to spot Carillion's perilous state.