Colorfill cells carrying same data

I have an Excel database with over 6,000 people in there which I inherited. Let's just say it's not the best in the world. A.o. place of residence is in a column called 'Address 3' where there also is additional address information. This makes it impossible to sort data on place of residence. Now I want to fill all rows carrying the word 'Penang' (so all inhabitants of this city will be filled), is there a fast way to fill all these cells/rows at once or do I have to do this manually?
Thank you in advance