Alignment issue for icons


I am using one of Chameleon theme’s style called “borderless icon-on-top” for adding icon over a button. By default it aligns it to the left of the caption but I need it aligned in the center. Can anyone help me with this.

Adding few lines of code:
Button adminButton = new Button();
adminButton.addStyleName(“borderless icon-on-top”);

Attaching an image of how it displays currently with just the chameleon theme.

Thanks in advance,