Example:

Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);

builder.writeln();

// Create some style with theme font properties.
Style style = doc.getStyles().add(StyleType.PARAGRAPH, "ThemedStyle");
style.getFont().setThemeFont(ThemeFont.MAJOR);
style.getFont().setThemeColor(ThemeColor.ACCENT_5);
style.getFont().setTintAndShade(0.3);

builder.getParagraphFormat().setStyleName("ThemedStyle");
builder.writeln("Text with themed style");

Example:

Document doc = new Document();

// Define fonts for languages uses by default.
doc.getTheme().getMinorFonts().setLatin("Algerian");
doc.getTheme().getMinorFonts().setEastAsian("Aharoni");
doc.getTheme().getMinorFonts().setComplexScript("Andalus");

Font font = doc.getStyles().get("Normal").getFont();
System.out.println(MessageFormat.format("Originally the Normal style theme color is: {0} and RGB color is: {1}\n", font.getThemeColor(), font.getColor()));

// We can use theme font and color instead of default values.
font.setThemeFont(ThemeFont.MINOR);
font.setThemeColor(ThemeColor.ACCENT_2);

Assert.assertEquals(ThemeFont.MINOR, font.getThemeFont());
Assert.assertEquals("Algerian", font.getName());

Assert.assertEquals(ThemeFont.MINOR, font.getThemeFontAscii());
Assert.assertEquals("Algerian", font.getNameAscii());

Assert.assertEquals(ThemeFont.MINOR, font.getThemeFontBi());
Assert.assertEquals("Andalus", font.getNameBi());

Assert.assertEquals(ThemeFont.MINOR, font.getThemeFontFarEast());
Assert.assertEquals("Aharoni", font.getNameFarEast());

Assert.assertEquals(ThemeFont.MINOR, font.getThemeFontOther());
Assert.assertEquals("Algerian", font.getNameOther());

Assert.assertEquals(ThemeColor.ACCENT_2, font.getThemeColor());
Assert.assertEquals(0, font.getColor().getRGB());

// There are several ways of reset them font and color.
// 1 -  By setting ThemeFont.None/ThemeColor.None:
font.setThemeFont(ThemeFont.NONE);
font.setThemeColor(ThemeColor.NONE);

Assert.assertEquals(ThemeFont.NONE, font.getThemeFont());
Assert.assertEquals("Algerian", font.getName());

Assert.assertEquals(ThemeFont.NONE, font.getThemeFontAscii());
Assert.assertEquals("Algerian", font.getNameAscii());

Assert.assertEquals(ThemeFont.NONE, font.getThemeFontBi());
Assert.assertEquals("Andalus", font.getNameBi());

Assert.assertEquals(ThemeFont.NONE, font.getThemeFontFarEast());
Assert.assertEquals("Aharoni", font.getNameFarEast());

Assert.assertEquals(ThemeFont.NONE, font.getThemeFontOther());
Assert.assertEquals("Algerian", font.getNameOther());

Assert.assertEquals(ThemeColor.NONE, font.getThemeColor());
Assert.assertEquals(0, font.getColor().getRGB());

// 2 -  By setting non-theme font/color names:
font.setName("Arial");
font.setColor(Color.BLUE);

Assert.assertEquals(ThemeFont.NONE, font.getThemeFont());
Assert.assertEquals("Arial", font.getName());

Assert.assertEquals(ThemeFont.NONE, font.getThemeFontAscii());
Assert.assertEquals("Arial", font.getNameAscii());

Assert.assertEquals(ThemeFont.NONE, font.getThemeFontBi());
Assert.assertEquals("Arial", font.getNameBi());

Assert.assertEquals(ThemeFont.NONE, font.getThemeFontFarEast());
Assert.assertEquals("Arial", font.getNameFarEast());

Assert.assertEquals(ThemeFont.NONE, font.getThemeFontOther());
Assert.assertEquals("Arial", font.getNameOther());

Assert.assertEquals(ThemeColor.NONE, font.getThemeColor());
Assert.assertEquals(Color.BLUE.getRGB(), font.getColor().getRGB());