Orange feathers, along with all coloured feathers gathered from the Hunter skill, can be used in place of regular white feathers with the Fletching skill. Despite the difference, bolts and arrows created still come out with white feathers and have no extra properties. They are colourful and can be sold at the VarrockFancy Dress Shop. However, unlike white feathers, they can not be used for Fishing.
Originally, copper longtail feathers were brown feathers. At some point, they were renamed to orange feathers to better match the colour of the birds they came from. Before this change, orange feathers were already an existing item obtained from golden warblers. To avoid confusion, their feathers were also renamed, to yellow feathers.