A text indicator displays an alphanumeric string and uses color to indicate that the data value is above or below specified thresholds. You can define up to four thresholds and five colors.
Optionally, an 
advanced setting in measures portlets to Parse string values as numeric allows string columns to be used as numeric indicators.
See also:
- About Indicator Thresholds
- Indicator Portlet Options - Standard License
- Indicator Portlet Options - Measure Factory License
- Editing Color Properties in a Portlet