Bug in col2rgb?

On 3/31/2009 12:29 PM, hadley wickham wrote:

col2rgb("#00000079", TRUE)

      [,1]
red      0
green    0
blue     0
alpha  121

col2rgb("#00000080", TRUE)

      [,1]
red    255
green  255
blue   255
alpha    0

col2rgb("#00000081", TRUE)

      [,1]
red      0
green    0
blue     0
alpha  129


Any ideas?

The #00000080 string converts into the hex integer 0x80000000, which, by 
an unfortunate coincidence, is the NA_integer value.  Since NA_integer 
becomes the background colour, you get white instead of black with 
alpha=0x80.

This can probably be fixed (if you have a string, there's a different 
way to know you have an NA).  Want to work out a patch?  The file to 
look at is src/main/colors.c.