Cato Blue is an informal term describing a New Zealand railway locomotive livery (resulting from the combination of blue, grey and yellow in the colour scheme) found in common usage amongst the railfan community. The livery was first worn on DFT 7160 as a variation of the New Zealand Rail blue livery. With the introduced of Tranz Rail on 18 October 1995, the livery was adopted to replace New Zealand Rails blue livery, which was introduced in 1991. The scheme was known as Cato Blue after its creator, Cato Partners. DFT 7199 was the first locomotive repainted in the livery after Tranz Rail took over the rail system.