• Highlight empty cells where the drop down option is wanted.
• Look on Data tab & click Data Validation. 
• Under allow: use option LIST
• Using function for Source, highlight the list of options that you want to use for the list. 

To Add Color

• Highlight cells within the table that you want color added to. 
• Click Conditional Formatting and New Rule. 

• Using these options, pick the cell you would like to edit:

• In the Format box, pick fill option and color of choosing (grey here). 

11_23_2016