The Tutorial uses Print methods (Rules) designed to separate Food orders onto separate cards. It combines Drink orders onto single cards. I designed it this way because that is how I want it for my venue. It also gives opportunity to show 2 different methods, which you can extrapolate for your own needs.
So if you want Food to be combined on 1 card (the same as Drink), use the same Rules for Food as you do for Drink.
If the colors do not work in Light Theme, then change them in the Printer Templates.
You need to modify the setup as you see fit, for your needs.