How to change style of the P element within the editor?

/*
* Font face
*/
// List of fonts available in the toolbar combo. Each font definition is
// separated by a semi-colon (;). We are using class names here, so each font
// is defined by {Combo Label}/{Class Name}.
font_names : 'Comic Sans MS/FontComic;Courier New/FontCourier;Times New Roman/FontTimes',

// Define the way font elements will be applied to the document. The "span"
// element will be used. When a font is selected, the font name defined in the
// above list is passed to this definition with the name "Font", being it
// injected in the "class" attribute.
// We must also instruct the editor to replace span elements that are used to
// set the font (Overrides).
font_style :
{
element : 'span',
attributes : { 'class' : '#(family)' },
overrides : [ { element : 'span', attributes : { 'class' : /^Font(?:Comic|Courier|Times)$/ } } ]
},