title: Color the group in ggplot violin plot
body: <p>I am new to R programming. 
  Stuck while plotting ggplot violin plot.
  I wish to give color <code>blue</code>, <code>green</code> and <code>red</code> color to my 3 groups.
  Here is my dataframe: </p>
  
  <pre><code>&gt; print(employee_withoutEmployeeID[1:5,])
  &gt; 
    EnvironmentSatisfaction JobSatisfaction WorkLifeBalance
  1                       3               4               2
  2                       3               2               4
  3                       2               2               1
  4                       4               4               3
  5                       4               1               3
  </code></pre>
  
  <p>What I am trying is:</p>
  
  <pre><code>png(file="answer5.png")
  answer5 &lt;- ggplot(stack(employee_withoutEmployeeID), aes(x = ind, y= values) )
  answer5 + geom_violin()  + scale_fill_manual(values=c("#0000FF", "#00FF00", "#FF0000")) + 
    labs(title="Answer 5", 
         subtitle="",
         caption="Answer 5",
         x="Measure",
         y="Rating")  
  dev.off()
  </code></pre>
  
  <p>I am getting my violin plot plotted correctly, but there is no color fill. I am not sure, how and where to use <code>scale_fill_manual</code>
  Please suggest</p>