title: Issue in using scale colour manual in geom bar
body: <p>My data looks like:</p>
  
  <pre><code>AA  Extracellular   Intracellular
  A   2.23        5
  B   8.6         5
  C   13.5        5
  </code></pre>
  
  <p>Code looks like:</p>
  
  <pre><code>rdatamy&lt;-read.table("rat.txt",header=TRUE) # load the File
  molten2&lt;-melt(rdatamy,id.vars="AA",measure.vars=c("Extracellular","Intracellular"))#melt
  plot2&lt;-ggplot(molten2,aes(x=AA,width=0.3,y=value,colour=variable))+ 
  geom_bar(position='dodge',stat="identity") + scale_color_manual(values=c("Intracellular" = 
  "cyan","Extracellular" = "gold2"))
  </code></pre>
  
  <p>So, I am plotting a barpolot to compare 2 different things. </p>
  
  <p>The color they get are not the ones, I mention in scale color manual. However, the same color scheme works in geom_point for bubble plot over same variables. If I use <code>fill=variable</code> the bars get filled with some different colours. Below is my <code>geom_point()</code> code:</p>
  
  <pre><code>plot1&lt;-ggplot(molten, aes(x = variable, y = AA, size = value, colour = variable)) + 
  geom_point()+scale_color_manual(values=c("Intracellular" = "cyan","Extracellular" = 
  "gold2","TM" = "lightpink4"))+ scale_size(range = c(0, 10),name="")
  </code></pre>
  
  <p>Please help me understand this.</p>