Conditional formating in excel

Create a proper data. 

Create a drop-down list. 

Go to data tab and click data validation

Select list option

Select source

Go to conditional formatting option

Go to new rules

Go to (use a formula to determine which cells to format).

CellAddress first cell (product)

CellAddress drop-down cell

Remove dollar sign

Go to format option

Go to fill option and select a color.

Select any one option and highlight same product details