gtk: is there a way of setting the `light/dark' style fields from a gtkrc file?

[Miles Bader <miles@lsi.nec.co.jp>]

I downloaded the new `gtk-engines-icegradient' package, which is cool,
but I like a dark theme, so I copied the IceGradient theme and changed
the colors to be darker, e.g.:

  fg[NORMAL]       = "#E5E5E5"
  fg[ACTIVE]       = "#E5E5E5"
  bg[NORMAL]       = "#404040"
  bg[ACTIVE]       = "#505050"
  (etc)

This gives a dark general color to things, _however_, the 3d-ness
doesn't look very good, because the `highlight' color that gets used is
much too dark.  I looked at the source code for the icegradient engine,
and notice that it seems to get that highlight color from
`style->light_gc[state_type]', and if I try to do something like
`light[...] = ...' in my gtkrc file, it gives an error, so I guess this
field is automatically calculated.

My question: is there anyway to influence how gtk calculates the `light'
(and perhaps `dark') colors, so they look better with my dark color
scheme?  It seems like the method it uses only works well with bright
colors.

Thanks (and apologies if I'm totally off-base about how this stuff works),

-Miles
-- 
80% of success is just showing up.  --Woody Allen