Image 1: New/Edit Item Form
From New/Edit Item form user can select one of predefined categories.
Image 2: View Item Form
View Item form shows selected categories icons and/or category name according to column settings.
Image 3: List View
List View shows categories and/or category name according to column settings.
Image 4: List View
After user put mouse on category, advanced tool tip will be shown (SharePoint Theme or Simple style).
Image 5: Category Column Settings
These settings change displaying mode for list view and view item form.