title: Define color manually on both point and line in ggplot (R)
body: <p>I used ggplot function to plot the figure, 
  Here is my code for plotting, it combine three different data set.</p>
  
  <pre><code>pp&lt;-ggplot(model_mean_homo,aes(x=m_tau,y=track_err,colour=model,group=model))+geom_line(size=2) 
  pp&lt;-pp+geom_line(data=model_topN,aes(x=model_topN$m_tau,y=model_topN$track_err,colour=top_N,group=top_N)) 
  pp&lt;-pp+geom_point(data=model_mem,aes(x=model_mem$m_tau,y=model_mem$track_err,colour=model))
  </code></pre>
  
  <p><a href="http://i.stack.imgur.com/LD1k7.png" rel="nofollow">enter image description here</a></p>
  
  <p>I want to change to color for both line and point.
  I tried the following code: </p>
  
  <pre><code>pp&lt;-scale_color_manual(values = c("ECMWF"="red","NCEP"="blue","ECMWF+NCEP"="green","5"="red1","10"="orange","15"="yello3","20"="green3","15"="black"),limits = c("ECMWF","NCEP","ECMWF+NCEP","5","10","15","20"))
  </code></pre>
  
  <p>But the console only shows :</p>
  
  <pre><code>&lt;ggproto object: Class ScaleDiscrete, Scale&gt;
      aesthetics: colour
      break_info: function
      break_positions: function
      breaks: waiver
      call: call
      clone: function
      dimension: function
      drop: TRUE
      expand: waiver
      get_breaks: function
      get_breaks_minor: function
      get_labels: function
      get_limits: function
      guide: legend
      is_discrete: function
      is_empty: function
      labels: waiver
      limits: ECMWF NCEP ECMWF+NCEP 5 10 15 20
      map: function
      map_df: function
      na.value: NA
      name: waiver
      palette: function
      range: &lt;ggproto object: Class RangeDiscrete, Range&gt;
          range: NULL
          reset: function
          train: function
          super:  &lt;ggproto object: Class RangeDiscrete, Range&gt;
      reset: function
      scale_name: manual
      train: function
      train_df: function
      transform: function
      transform_df: function
      super:  &lt;ggproto object: Class ScaleDiscrete, Scale&gt;
  </code></pre>
  
  <p>How do I change the color for this kind of plot?</p>
  
  <p>Below is the data set sample:</p>
  
  <pre><code>head(model_mean_homo)
      YY      model filetype m_tau track_err datano
  1 2015 ECMWF+NCEP ensemble     0  35.44013    307
  2 2015 ECMWF+NCEP ensemble     6  36.92316    300
  3 2015 ECMWF+NCEP ensemble    12  43.44246    297
  4 2015 ECMWF+NCEP ensemble    18  48.68222    284
  5 2015 ECMWF+NCEP ensemble    24  57.60609    280
  6 2015 ECMWF+NCEP ensemble    30  64.35638    268
  
  head(model_topN)
      YY model filetype m_tau track_err datano top_N
  1 2015  NCEP ensemble     0  26.67671    618     5
  2 2015  NCEP ensemble     6  27.97913    609     5
  3 2015  NCEP ensemble    12  31.18090    594     5
  4 2015  NCEP ensemble    18  34.23283    575     5
  5 2015  NCEP ensemble    24  37.31816    557     5
  6 2015  NCEP ensemble    30  43.25841    541     5
  
  head(model_mem)
      YY model filetype m_member m_tau track_err datano
  1 2015 ECMWF ensemble        0     0  44.96796    397
  2 2015 ECMWF ensemble        0     6  47.30694    390
  3 2015 ECMWF ensemble        0    12  55.97534    383
  4 2015 ECMWF ensemble        0    18  61.36752    367
  5 2015 ECMWF ensemble        0    24  69.96123    363
  6 2015 ECMWF ensemble        0    30  79.56475    345
  </code></pre>