Read this in a What's New document for SAP BO 4.1
2.12.4 Custom color palettes and color assignment in charts (New)
You can personalize the appearance of charts in Web Intelligence reports by defining colors to dimension objects
by using customized color palettes. You can set this color assignment on one or more dimension objects
throughout all of the charts in a document using the Set as Default Colors option.
The automatic color assignment to a chart’s legend items generated by a palette can be made set to all instances
of a chart in a document using the “Set as Default Colors” option. The default colors do not change when you
apply refresh on open, drilling or filtering to a document
I am on SAP BO 4.1. SP2 but don't see the "Set as Default Colors" option. Where is it?