You might try this method to achieve a warm almost copper effect.
Originally Posted by gareth harper
First dilute the bleach used in sepia toning at least 3 times weaker than suggested in the instructions, ie most say 1 to 9 use 1 to 30 or more. Bleach the print for about 20 to 30 seconds and wash then sepia tone it in the normal strength toner. All that will happen is that the highlights only will be slightly changed to a delicate sepia tone. Wash the print and then bleach in a normal strength sepia bleach until the blacks loose the richness you would normally see in a deep rich black. Wash the print and place it into a selenium toner bath, I use a 1 to 9 dilution, and allow it to re-develop
until it reaches a colour that you like. It can take quite a long time
sometimes 30 mins or more.