Are you finding that validation errors are being displayed differently to those from required fields? Can you provide any screen shots of what you see the required fields and validation errors currently?
Display options for erros are configured in the Harness rule as shown below (7.1.9 screen shot). In order for the error to be displayed next a field it needs to be present on the screen of course.
1. Using LiveUI tool, open the harness that contains the concerned section. Traverse to "Scripts & Styles" tab, and check if there is an addtional css applied to this harness (under Styles sheets).
2. Additionally, open the Skin rule and under Component Styles tab, click on the Dynamic Layout menu. Choose Errors from that list. Now check whether any particular style has been configured for the errors.
You can compare these settings with any OOTB skin, say, pyEndUser71 or pzDesignerStudio.