Free WordPress.com users can use CSS inline by adding the coding within the post editor. Others will place the styles inside a CSS style sheet or the CSS Customization area. Either way, a frequent use of CSS involves styling blockquotes.
I’ll run through a few ways in which you can use CSS to style your blockquotes. For all of these examples, you can easily change the colors I use by grabbing the hex code of your desired color and swapping it in for the color I use in the example.
Similarly, you can change the thickness of the borders in my examples by increasing or decreasing the numbers.
Ok, let’s get into how to style blockquotes in WordPress…
Source: How to Style Blockquotes in WordPress Using CSS | Pagely®