Use the settings in this page to enable clash highlighting and select the colours used to highlight clashes in the Navisworks Coordination Issues Add-in.
Enable - Use this check box to turn clash highlighting on and off. This determines whether clashes between models loaded from Model Corordination are displayed in the selected colors.
Primary/Secondary color - If you have enabled clash highlighting, use the drop-down lists to select which colors the clashes are displayed in. The primary color is applied the primary model, the model against which other models are clashed. The secondary color is applied to the other model. See the Model Coordination help for more information about primary and secondary models.