Layer Style Overrides override the default style for your layer in cases that match set data qualifications
Every layer will have at least one style - the default style. However, you are able to add style overrides which will apply to features that match the field value that you set in the style override.
Creating a new Line Style
Before you can create a new line style, create the fields for the layer first.
In the field's advanced settings, create the values that will appear in the pick list window in feature details.
Once values have been added you can create style overrides.
In the Line Style box, click edit. Under default, click the + sign.
In the field and value box, select the field you want to be represented.
Select the color and style of line that will be based off the value in the designated field.
Once complete, click Save.
When in the results or feature details window, the line color and style will change based off of the value set.