LitCharts assigns a color and icon to each theme in The Book Thief, which you can use to track the themes throughout the work.
Death
Words and Language
Books
Stealing and Giving
Color, Beauty, and Ugliness
Summary
Analysis
Meanwhile Rudy has been going to Hitler Youth meetings, which haven't worked out well. His problems are the hearing-impaired Tommy Müller and the tyrannical Youth leader, Franz Deutscher. Tommy keeps messing up the precise marching lines because he can't hear the commands, and Deutscher mocks him for it. Rudy stands up for Tommy and then Deutscher makes them both do laps and push-ups on a muddy field. Later they tell Liesel about it and Tommy tries to apologize to Rudy. Rudy asks Liesel for a kiss, but she refuses again, despite his pitiable state. Later Liesel will realize that it was these kinds of days that fed their desire for stealing.
Rudy is developing his own ethical code at the same time Liesel is. Rudy has a naturally tempestuous nature, but he shows he will stand up for a weaker person (Tommy) even to the point of putting himself at risk. Franz Deutscher appears as a cruel, unsympathetic child with power. Like Hitler, Deutscher uses his power, small though it is, to cause suffering to those weaker than himself.