Discuss strategies to ensure integrated, coordinated error messages that are consistent across an application

“Balancing Function and Fashion” Please respond to the following:
Error messages are a key part of an overall interface design strategy of guidance for the user. Discuss strategies to ensure integrated, coordinated error messages that are consistent across an application. 
Choose the one topic covered in Chapter 11 (error messages, non-anthropomorphic design, display design, window design, and color) that creates the biggest challenge to achieving balance between function and fashion. Support your response.
Note: Requirement is one and half page with references