title: ggplot multiple boxplots and stat_summary position
body: <p>I have the following code. I'd like to change the color of the boxplots so they all have the same fill color (grey).
  Also I'd like to have the stat_summary texts to stick to the bottom of each barplot but vjust only seem to provide relative position?</p>
  
  <p>Thanks</p>
  
  <pre><code>boxp &lt;- ggplot(mtcars, aes(as.factor(cyl), wt, fill=as.factor(am)) ) +
    geom_bar(position = "dodge", stat = "summary", fun.y = "median") +
    geom_boxplot(outlier.shape = NA, width=0.2, color = "black", position = position_dodge(0.9)) +
    stat_summary(aes(label=round(..y..,2)), fun.y=median, geom="text", size=8, col = "white", vjust=8, position = position_dodge(0.9)) +
    stat_summary(fun.y=mean, geom="point", shape=18, size=4, col="white", position = position_dodge(0.9)) +
    labs(x = "Conditions", y = "Medians") +
    scale_y_continuous(limits=c(0,7),oob = rescale_none) +
    theme_bw()
  boxp
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/IHiwL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IHiwL.png" alt="enter image description here"></a></p>