title: rgb() with ggplot2 in R
body: <p>In ggplot2, we have the option of setting colours by name or hex code. Is there any way to use rgb values in the same way? I searched the docs but the quick answer seems to be 'no'. (The reason I would like to use rgb is that I have some colours that I am going to use for some plots, and I have them all in rgb format. I can get the hex from places like <a href="http://www.w3schools.com/colors/colors_converter.asp" rel="noreferrer">here</a>, but it would be great if I could just enter the values straight into <code>ggplot()</code>.</p>