GTK built-in color names (eg: "green", "purple")

[John W <jwdevel gmail com>]

Is there a way to re-define the RGB values of built-in color names in GTK?
Perhaps using .gtkrc? Ideally I don't want to compile a custom binary...

Background, for those interested:

I use Vim, both the commandline version (vim) and GUI vesrion (gvim).
The gui version is built on GTK.

In my color schemes for Vim, I use names like "green" and "purple" in
various places.
In Vim, these use the X11 color values, taken from rgb.txt. That is
what I am used to, and what I want to also use in GVim.

However — and here I am speculating — GVim seems to use GTK to
interpret color names, and GTK has a different notion of what "green"
and "purple" mean than X11.

For instance, "green" in vim is #00FF00, and "green" in gvim is #008000.

I suspect that GTK uses the W3C color values, whereas X11 obviously
uses the X11 color values
(http://en.wikipedia.org/wiki/X11_color_names#Clashes_between_web_and_X11_colors).
That certainly matches what I see visually.

So back to the point: is there any way to change GTK's mapping for color names?
Or perhaps have GTK use X11 color names?

Thanks
-John