You make a new sticky note, type in a word (for example "test") and select it. Click right, go to fonts and then style. Make the word in het style you want and add it to your favourite styles and give it a name (for example "MyStyle"). And save it. Now, delete the sticky your just made.

Go to your sticky with the "problem" and select all. Right-click and go to fonts and style Click on favorite styles and select "MyStyle" Click apply This should do the trick.

Greetings Carl

You make a new sticky note, type in a word (for example "test") and select it.
Click right, go to fonts and then style. 
Make the word in the style you want and add it to your favourite styles and give it a name (for example "MyStyle"). And save it. 
Now, delete the sticky your just made.

Go to your sticky with the "problem" and select all. 
Right-click and go to fonts and style 
Click on favorite styles and select "MyStyle" 
Click apply

This should do the trick.