When adding Categories, you can set the "Add Shifts Default Display Color". When you Add New Shifts and choose that Category, the Display Color will automatically be set to that Default color. You can always change the Display Color of an individual shift by changing it in the Display Color dropdown.

Create a new Category with Add Shift Default Settings:
From any Schedule View: 

• In the Category dropdown, choose Add/Edit Categories to open the Add/Edit Categories window 
• Enter the Category Name and Abbreviation (Ex. Night Shifts and NT) 
• Enter any default Display Color setting you like in the lower box 
• Click Add Now 
• The window remains open for you to add more categories - when done, close the window to go back to your schedule

Changing the Add Shift Default Settings of an Existing Category:
From any Schedule View: 

• In the Category dropdown, choose Add/Edit Categories to open the Add/Edit Categories window 
• Scroll down to the bottom box - Edit Current Categories 
• In the dropdown, choose the Category name to Edit 
• The Category details will appear below 
• Choose the Default Color you want from the dropdown 
• Click the Save button 

Now when you click Add Shifts on any Schedule View and choose this Category, your default color will be automatically entered for you (any of the default info can be changed).