A method comprising: receiving, by processing circuitry of a first network device, an indication of a route target, one or more underlay tunnels configured to support a service route, and a color of the one or more underlay tunnels, the service route being a logical route configured to transport network traffic from a service host device that generates network traffic associated with a first network service of a plurality of network services to a customer edge device; wherein the color is a generic label which identifies a respective underlay tunnel as being a part of a common type such that tunnels assigned to a particular color have one or more characteristics in common; defining, by the processing circuitry and based on the indication, a first transport class of a plurality of transport classes, wherein the first transport class is a service-specific group comprising the route target and specifying the one or more underlay tunnels and the color of the one or more underlay tunnels, and wherein the route target of the first transport class is different from route targets of each other transport class of the plurality of transport classes; storing, by the processing circuitry, the first transport class of the plurality of transport classes; receiving, by the processing circuitry, the network traffic associated with the first network service of the plurality of network services; identifying, by the processing circuitry, the service route for the first network service of the plurality of network services; and forwarding, by the processing circuitry and based on an association between the service route and the first transport class of the plurality of transport classes, the network traffic associated with the first network service of the plurality of network services along the one or more underlay tunnels specified by the first transport class. receiving, by processing circuitry of a first network device, an indication of a route target, one or more underlay tunnels configured to support a service route, and a color of the one or more underlay tunnels, the service route being a logical route configured to transport network traffic from a service host device that generates network traffic associated with a first network service of a plurality of network services to a customer edge device; wherein the color is a generic label which identifies a respective underlay tunnel as being a part of a common type such that tunnels assigned to a particular color have one or more characteristics in common; defining, by the processing circuitry and based on the indication, a first transport class of a plurality of transport classes, wherein the first transport class is a service-specific group comprising the route target and specifying the one or more underlay tunnels and the color of the one or more underlay tunnels, and wherein the route target of the first transport class is different from route targets of each other transport class of the plurality of transport classes; storing, by the processing circuitry, the first transport class of the plurality of transport classes; receiving, by the processing circuitry, the network traffic associated with the first network service of the plurality of network services; identifying, by the processing circuitry, the service route for the first network service of the plurality of network services; and forwarding, by the processing circuitry and based on an association between the service route and the first transport class of the plurality of transport classes, the network traffic associated with the first network service of the plurality of network services along the one or more underlay tunnels specified by the first transport class.