title: visualize a list of colors/palette in R
body: <p>I have following data.frame with rgb values. Hence each row indicates a color. </p>
  
  <pre><code>&gt; ddf
         r     g     b
  1  0.374 0.183 0.528
  2  0.374 0.905 0.337
  3  0.051 0.662 0.028
  4  0.096 0.706 0.898
  5  0.876 0.461 0.628
  6  0.415 0.845 0.286
  7  0.596 0.070 0.523
  8  0.724 0.101 0.673
  9  0.847 0.434 0.937
  10 0.588 0.885 0.604
  11 0.481 0.366 0.337
  12 0.142 0.075 0.276
  13 0.819 0.737 0.658
  14 0.910 0.722 0.979
  15 0.969 0.012 0.451
  16 0.887 0.536 0.123
  17 0.432 0.967 0.446
  18 0.927 0.125 0.332
  19 0.381 0.646 0.656
  20 0.040 0.898 0.798
  &gt; 
  &gt; dput(ddf)
  structure(list(r = c(0.374, 0.374, 0.051, 0.096, 0.876, 0.415, 
  0.596, 0.724, 0.847, 0.588, 0.481, 0.142, 0.819, 0.91, 0.969, 
  0.887, 0.432, 0.927, 0.381, 0.04), g = c(0.183, 0.905, 0.662, 
  0.706, 0.461, 0.845, 0.07, 0.101, 0.434, 0.885, 0.366, 0.075, 
  0.737, 0.722, 0.012, 0.536, 0.967, 0.125, 0.646, 0.898), b = c(0.528, 
  0.337, 0.028, 0.898, 0.628, 0.286, 0.523, 0.673, 0.937, 0.604, 
  0.337, 0.276, 0.658, 0.979, 0.451, 0.123, 0.446, 0.332, 0.656, 
  0.798)), .Names = c("r", "g", "b"), class = "data.frame", row.names = c(NA, 
  -20L))
  </code></pre>
  
  <p>How can I visualize these colors? This can be either as bars of color or a palette or a pie chart. I tried to use following method but could not fit it in my data:</p>
  
  <pre><code>pie(rep(1,20), col=rainbow(20)) 
  </code></pre>