First Greater Manchester originally branded their frequent services as an "Overground". Based on the London Underground network where each frequent service is given a recognisable colour, each Overground service was also allocated its own colour line. The concept was a prominent fixture on network maps and coloured vinyls applied to the buses frequently serving those routes. However, the brand has largely been dropped. The colours still remain on network maps but the vinyls for the most part have disappeared from the fleet's vehicles. The coloured routes are those with Monday - Saturday daytime frequencies of 15 minutes or better. This has allowed services such as the 67, 98, 519, 540 and 598 to keep their coloured line despite the frequency of the service dropping under the 10 minutes minimum frequency.