You have to use two functions. The first one is WordPress’ built-in shortcode_atts() function, which combines user shortcode attributes with native attributes and fills in the defaults where needed. The second function is the extract() PHP function, which does what its name suggests: it extracts the shortcode attributes.
‘bg_color’ => ”,
You can take our shortcode one step further and add the ability to pass some content as an argument, which in this case will be a heading for the list of recent posts. To do this, we use a second parameter, $content, in the callback function and add it as an h3 heading before the list. The new function is as follows: