Need your help: colors in data charts PPT 2003 versus 2007

Colors in data charts. This 2003-2007 compatibility issue drives me crazy. Many of my clients still use Office 2003. Does anyone have a solution?
  • PPT 2003 uses Microsoft Graph for data charts, PPT 2007 Excel
  • I create a chart in 2007
  • I save the 2007 PPTX in 2003 PPT format
  • I (or my client) opens the 2003 PPT file and
  • right-clicks the chart to open it: all the colors are off...
I have to change every color manually using RGB codes to set them permanently to the correct value in 2003.
There must be a better way to do this! Let me know if you know.