title: R: How to change the color scheme (14 colors needed) in ggplot
body: <p>I used the following code to create a plot using ggplot:</p>
  
  <pre><code>m = ggplot(derv, aes(x=Date, y=derv, colour = Season)) + geom_point() 
  m2 = m+geom_abline(intercept = 0, slope = 0)
  m3 = m2 + geom_abline(intercept = 2.578269274, slope = 0)
  m3 = m3 + geom_abline(intercept = -1.4242559021, slope = 0) 
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/J5lmJ.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/J5lmJ.jpg" alt="enter image description here"></a></p>
  
  <p>This plot looks beautiful but for some intervals such as 2010sp and 2010au, it is hard for me to tell when the color changed. So I want to change the color scheme of this plot.</p>
  
  <p>and I have tried the following code:</p>
  
  <pre><code> m3+scale_color_brewer(palette="Dark2")
  </code></pre>
  
  <p>but I am getting a warning message:</p>
  
  <p><a href="https://i.stack.imgur.com/qS3TT.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/qS3TT.jpg" alt="enter image description here"></a></p>
  
  <pre><code>2: In RColorBrewer::brewer.pal(n, pal) :
  n too large, allowed maximum for palette Dark2 is 8
  Returning the palette you asked for with that many colors
  </code></pre>
  
  <p>and I have checked the palettes available, the biggest one contains 12 colors but I need 14, so I am wondering if there is way to resolve this issue.</p>