Paragraphs of text are a fundamental core of web content, so it's important to display them in a fashion that is optimally readable to the majority of your audience without requiring them to change their display settings. For people who do need to customize display of text to make it easier to read, it's important to support this customization rather than forcing them to read the text the way you specify.
For the most part, this means applying typesetting best practices, which predate the web.
Some people with reading difficulties or visual impairments need to customize the display of text to make it easier to read. When text is presented as an image of text, that limits their ability to change the appearance of that text. So wherever possible, use text along with CSS to apply styling (such as color, typeface, or size).
If you use an online content editor to write content, the styling will happen automatically. If you feel that you need text that deviates from the style, formatting options...