any errors or warnings?
is tamañoDeLetra a list of labels or buttons?
later you try to set a button fontsize and label fontsize using the same component
you should initialize the list of your components using component blocks and have a list for labels and another list for buttons ...
see also
How to work with the advanced features
A Multiple Choice Quiz: How to work with the advanced features
Taifun
Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by 
Taifun.