The interior stonework is a mixture of sandstone from the Barrabool Hills and Waurn Ponds limestone, with contrasting stripes of Victorian bluestone, giving the cathedral a warm colouring, when most other grand 19th century public buildings are faced in light grey sandstone imported from other states. It is also quite different in appearance to the bluestone Gothic of St Patrick's Roman Catholic cathedral on the eastern hill of the city. Because the spires are built from Sydney sandstone and are 40 years newer, they are a different and darker colour than the older parts of the building.