In order to apply text formatting, just select the words and look for the given options. These options are available on the Outline and Design views.
To edit the text size, there are preset Styles to choose from. Text color can't be changed for specific paragraphs or headings, but you can add colored highlighting. You can also create a custom Palette and choose colors for text, more details on that here. This is a Premium feature.
Other formatting options include the standard Bold, Italic, Underline, Bullet, Numbering, and Hyperlinks.