title: ggplot2 geom_point change color by values of a column
body: <p>I'm using ggplot2 in order to make a line plot (y=sum of income, x=date)with points representing sales (y=intersection of line plot, x=promotiondate).</p>
  
  <p>I have another column that represents the type of promotion and I want to change the color of points by the different values of this column.</p>
  
  <pre><code>p1&lt;- ggplot(df,aes(x= date,y = income))
  
  p1 + geom_line(col="red") + 
    geom_point(aes(x=df$promotiondate, y=df$income))+
    scale_color_manual(name="promotioncode", values = c("0"="white","P_1##1##1"="red","P_120##1##1"="blue","P_21##1##1"="green", "P_30##1##1"="yellow", "P_50##1##1"="purple", "P_66##1##1"="black"), labels=c("0","P_1##1##1","P_120##1##1","P_21##1##1", "P_30##1##1", "P_50##1##1", "P_66##1##1"))
  </code></pre>
  
  <p>This is what I obtain</p>
  
  <p><a href="https://i.stack.imgur.com/fGV32.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fGV32.png" alt="enter image description here"></a></p>
  
  <p>As you can see all the points are black.</p>
  
  <p>How can I make the colour of the points change based on the values of the columns promotioncode?</p>
  
  <p>Thanks in advance</p>