Button Caption Style

How i can change button caption style for few buttons and rest will use original style.

I had given button.setStyle(“styleName”);
but nothing happens. When i took the source of the generated html… i can see it is not changing the caption div … the style is appearing inside the outside div element

please help

Use CSS, e.g

button.setStyleName("myStyle"); // sets the classname in the DOM
/* apply CSS */
.v-button-myStyle .v-button-caption {
   color: red;