There was no dataset, so my dataset is a bit rubbish, and I'm not entirely sure what you mean with your question if a calculated field needs to be added.
I did however get a workbook that may help you further.
I've created the graph you showed in your screenshot and then added mood/colour. I've left percentages on the bars, which means it will calculate by all the different moods. I think you wanted to keep percentages on the top though. Adding a reference line will do that.
Hope this helps, give a shout if anything is unclear.
Exercise and Moods.zip 29.3 KB