This is a known problem with pivot charts. There's information in the
following MSKB article, which suggests recording a macro as you apply
the formatting:

Changing a PivotChart removes series formatting in Excel
http://support.microsoft.com/?id=215904

shadestreet wrote:
My Pivot Charts always reset the formats whenever I refresh or add
fields. Very frustrating. I checked the "Preserve Formmatting" and
unchecked "AutoFormat" in the pivot table that is used as the source
for the chart, but still doesnt fix my problem. Also have tried making
the chart type I want to use as the "default" but this wasn't of help
either.

Is this normal in excel 2003? Any solutions out there?


--
Debra Dalgleish
Contextures
http://www.contextures.com/tiptech.html