title: Format caption of gtsummary tables
body: <p>Hopefully this is not something very obvious I missed, but I am having a hard time finding how to format the caption of gtsummary tables.</p>
  <p>I am trying to reproduce the table found here. I love the left aligned grey caption: <a href="https://www.danieldsjoberg.com/gtsummary/articles/tbl_summary.html#gtsummary-functions-to-format-table" rel="nofollow noreferrer">https://www.danieldsjoberg.com/gtsummary/articles/tbl_summary.html#gtsummary-functions-to-format-table</a></p>
  <p><a href="https://i.stack.imgur.com/KcEuw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KcEuw.png" alt="enter image description here" /></a></p>
  <p>I am using the following code, but the caption <code>Table 1. Patient Characteristics</code> is shown centered and in black ink, but in the example is left aligned and grey.</p>
  <p>How can you format the caption of the gtsummary tables?</p>
  <pre><code>library(gtsummary)
  trial2 &lt;- trial %&gt;% select(trt, age, grade)
  
  trial2 %&gt;%
    tbl_summary(by = trt) %&gt;%
    add_p(pvalue_fun = ~style_pvalue(.x, digits = 2)) %&gt;%
    add_overall() %&gt;%
    add_n() %&gt;%
    modify_header(label ~ &quot;**Variable**&quot;) %&gt;%
    modify_spanning_header(c(&quot;stat_1&quot;, &quot;stat_2&quot;) ~ &quot;**Treatment Received**&quot;) %&gt;%
    modify_footnote(
      all_stat_cols() ~ &quot;Median (IQR) or Frequency (%)&quot;
    ) %&gt;%
    modify_caption(&quot;**Table 1. Patient Characteristics**&quot;) %&gt;%
    bold_labels() 
  </code></pre>
  <p><a href="https://i.stack.imgur.com/ffbJF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ffbJF.png" alt="enter image description here" /></a></p>