Just apply the patch to "/usr/share/themes/Radiance/gtk-2.0/gtkrc".
It somehow works instantly, i.e. it changes the appearance of the menu bar instantly. Don't know why ...
Caveats:
1) It's still called Radiance and not Bright.
2) One might still perceive some kind of embossed or glossy effect: maybe that's a perceptive interference with the background gradient but it doesn't show up in the pixel values.
(This might even depend on the type of display - not all liquid crystal display show a static image: some try to interpolate unrepresentable colors of RGB24 by alternating rapidly between two colors in 6 bit color channels bla bla etc.)
Found it. Solved it.
Just apply the patch to "/usr/share/ themes/ Radiance/ gtk-2.0/ gtkrc".
It somehow works instantly, i.e. it changes the appearance of the menu bar instantly. Don't know why ...
Caveats:
1) It's still called Radiance and not Bright.
2) One might still perceive some kind of embossed or glossy effect: maybe that's a perceptive interference with the background gradient but it doesn't show up in the pixel values.
(This might even depend on the type of display - not all liquid crystal display show a static image: some try to interpolate unrepresentable colors of RGB24 by alternating rapidly between two colors in 6 bit color channels bla bla etc.)