title: Is it possible to reorder only the facets of facet_wrap, without reordering the underlying factor levels?
body: <p>Sample data frame:</p>
  
  <pre><code>df &lt;- data.frame(x=rep(1:10,4),y=rnorm(40),Case=rep(c("B","L","BC","R"),each=10))
  </code></pre>
  
  <p>I can plot each time series in its own facet with:</p>
  
  <pre><code>ggplot(df,aes(x=x,y=y,color=Case)) + geom_line()+facet_wrap(~Case,nr=2,nc=2)
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/LDesk.png" rel="noreferrer"><img src="https://i.stack.imgur.com/LDesk.png" alt="enter image description here"></a>
  Now, suppose I want to change the facet order to (starting from top-left and going to bottom-right along rows) "L","B","R","BC". The usual suggestion here on SO is to do <a href="https://stackoverflow.com/questions/18066870/reorder-levels-of-facet-wrap-using-ggplot" title="this">this</a>. However, if I reorder the levels of factor <code>Case</code>, also the colors of the curves will be changed. Is it possible to reorder the facets, without changing also the order of the curve colors? I know it sounds like a weird question. The problem is that my report is a work in progress, and in a older version of the report, which I already showed to coworkers &amp; management, there were multiple plots more or less like this (with no <code>facet_wrap</code>):</p>
  
  <pre><code>ggplot(df,aes(x=x,y=y,color=Case)) + geom_line()
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/b7W8U.png" rel="noreferrer"><img src="https://i.stack.imgur.com/b7W8U.png" alt="enter image description here"></a></p>
  
  <p>In other words, by now people are used to associate the "B" to the red color. If I reorder, "L" will be red, "B" green, and so on. I can already hear the complaints...any way out of this one? </p>