A friend gave me this idea so all credit goes to her :)
When your going to a ribbon day or similar, plait your horse's mane as usual and use bands or thread the same colour. When it is finished, wrap one band around each plait of a contrasting colour (white band for a black mane, red bands for a white mane)
It looks really good and smart without being over the top.
Please comment if this is a goos idea :P