title: Colour specific node in igraph
body: <p>I am trying to colour node 6 and 7 regardless of whatever letter is selected from object 'd'. </p>
  
  <pre><code>g &lt;- graph_from_literal(1:2:3:4:5 -- 6:7)
  # Rename (sum up all the vertices)
  d &lt;- c("a", "b", "c", "d", "e", "f", "g","h", "i", "j")
  
  V(g)$name &lt;- sample(d, 7, replace=TRUE)
  colours &lt;- c("red")
  V(g)$color &lt;- ifelse(V(g)$name == c('a','e'), "white", colours)
  
  plot.igraph(g, layout=layout_with_dh, vertex.label=V(g)$name, 
  vertex.size=35,
  vertex.color=V(g)$color, #colors.r
  vertex.label.cex=0.7,
  )
  </code></pre>
  
  <p>I tried the ifelse() above but they don't seem to take numerical value. I would appreciate some help please. </p>
  
  <p>What I want is that node 6 is e.g. white and 7 is e.g. green and the rest of the other nodes are red.  </p>
  
  <p>Thank you!</p>