You can use HTML tags to change the color, formatting and style of your text. Even if you're new to HTML, the tags are relatively simple and you can probably learn them quickly.
Bold, italics, and underline
Bold example: <b> phrase in bold </b>
Italics example: <i> phrase in italics </i>
Underline example: <u> underlined phrase </u>
You can also use HTML comment tags if you want to annotate a list of cards that you plan to import into Mnemosyne.
Example: <! enter your comment here >