title: How do I change the outline colours of a boxplot with ggplot?
body: <p>My data has values which are all the same so they are coming up as just a line in a box plot. This, however, means that I can't tell the difference between groups as the fill doesn't show up. How can I change the outlines of the boxplot to be a specific colour. </p>
  
  <p>Note: I do not want all the outline colours to be the same colour, as in the next line of code:</p>
  
  <pre><code>library(dplyr)
  library(ggplot2)
  
  diamonds %&gt;% 
        filter(clarity %in% c("I1","SI2")) %&gt;% 
      ggplot(aes(x= color, y= price, fill = clarity))+
        geom_boxplot(colour = "blue")+
        scale_fill_manual(name= "Clarity", values = c("grey40", "lightskyblue"))+
        facet_wrap(~cut)
  </code></pre>
  
  <p>Instead, I would like all the plots for I1 (filled with grey40) to be outlined in black while the plots for SI2 (filled with lightskyblue) to be outlined in blue.</p>
  
  <p>The following don't seem to work</p>
  
  <pre><code>geom_boxplot(colour = c("black","blue"))+
  </code></pre>
  
  <p>OR</p>
  
  <pre><code>scale_color_identity(c("black", "blue"))+
  </code></pre>
  
  <p>OR</p>
  
  <pre><code>scale_color_manual(values = c("black", "blue"))+
  </code></pre>