title: How do I change the colour of the background to the x axis ticks in ggplot2?
body: <p>At the moment, my graph looks like this:</p>
  <p><img src="https://i.stack.imgur.com/nRYof.png" alt="Figure without x axis tick backgrounds" /></p>
  <p>However, I'd like to colour the background of the x axis tick so it resembles this:</p>
  <p><img src="https://i.stack.imgur.com/C8ylX.png" alt="Figure with x axis tick background" /></p>
  <p>I think I'm almost there, but can't figure out how to change the background to the x axis ticks, and not the writing itself.</p>
  <p>I changed the text colour using:
  <code>theme(axis.text.x = element_text(colour = Saltcolour)) </code></p>
  <p>Any help would be greatly appreciated!</p>