visualize a list of colors/palette in R

Question

I have following data.frame with rgb values. Hence each row indicates a color.

> 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
> 
> 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))

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:

pie(rep(1,20), col=rainbow(20)) 

Answer 1

I think the simplest option is scales. This also has the advantage of showing the hex values in the colours.

library(scales)
pal <- rgb(ddf$r, ddf$g, ddf$b)
show_col(pal)