Partica allows you to change most of the styles associated with the viewer and the articles. Styles are controlled through CSS, you can find the CSS editor in the title settings:
Here is a description of each of the default styles:
/* Article byline (author) */
.byline {color: #222; font-family: Arial; font-size:0.916rem; font-style: normal; font-weight: normal;}
/* Article Headline style when looking at an article */
.headline {color: #222; font-family: Arial; font-size:2.146875rem; font-style: normal; font-weight: normal;}
/* image cpation style */
.imageCaption {color: #222; font-family: Arial; font-size:0.916rem; font-style: normal; font-weight: normal;}
/* Article Headline style when displayed in a list */
.sectionHeader {color: #222; font-family: Arial; font-size:1.43125rem; font-style: normal; font-weight: bold;}
/* Article subheading style */
.subheading {color: #222; font-family: Arial; font-size:1.288125rem; font-style: normal; font-weight: normal;}
/* main Article body text style */
.text {color: #222; font-family: Arial; font-size:1.145rem; font-style: normal; font-weight: normal;}