Color error in ggplot2 (Error in grDevices::col2rgb(colour, TRUE) : invalid RGB specification)
<p>If I run:</p>

<pre><code>library(ggplot2)
ToothGrowth$dose &lt;- as.factor(ToothGrowth$dose)
bp&lt;-ggplot(ToothGrowth, aes(x=dose, y=len, fill=dose)) +
    geom_boxplot()
bp
</code></pre>

<p>I see the error: Error in grDevices::col2rgb(colour, TRUE) : invalid RGB specification.  </p>

<p>If I run the identical code on my other computer, I get the expected plot.  I am guessing that some plotting parameter is the culprit, but I have no idea how to find it.  What's going wrong?</p>

<p>The computer that behaves strangely is Mac OS X 10_11_3 running R 3.2.2 via RStudio 0.99.489</p>