Re: Axis Label Format in webi 3.1 ?

I don't have a 3.1 image up to check, but the following guide says it is there:

http://help.sap.com/businessobject/product_guides/boexir31SP3/en/xi31_sp3_webi_rich_en.pdf

Page 184 -

To format axis label text, borders, and background

1. Right-click the chart and click Format.
2. Click Yes next to the Appearance > X/Y/Z Axis > Label property. The property becomes a property group and the object name appears on the label.
3. Select Show object name to show the object name on the label.
4. Type the text into Other label if you want to assign custom text to the label in place of the object name.
5. To format the text, click ... next to Text Format to open the "Text Format" dialog box.
6. Use the "Text Format" dialog box to format the text.  You can set many of the properties in the "Text Format " dialog box directly from the property list, where they appear beneath Text Format.
7. Click ... next to Borders and use the "Border Editor" to format the label borders.

Did you try that?