To do this you need to open the .rpt file containing the report template you would like to edit in SAP Crystal Reports. ShipWeight only contain a Crystal Reports viewer not a Crystal Reports editor. When the report is open you can select the text field or text fields you would like to change and then use the Formatting toolbar to change the color (1), size (2) or type (3).
If you rather would prefer the Format Editor you can open this by right clicking on the text field and select the Format Text.. option to open the Format Editor.
In the Format editor it is possible to set Common properties, Border properties, Font Properties, Paragraph properties and Hyperlink properties to the text field.