Running Precise. I am tweaking the ambiance theme to my taste.
Yet I can't locate where I can modify the background color of the browser's tab bar (I suspect its value instruction to be somewhere in the gtk-widget or gtk-3 style files). See image:

Thanks in advance.

-------------------EDIT-----------------------

Solution:

Edited the following files:

• /usr/share/themes/MyTheme/gtk-2.0/apps/chromium.rc ( style "chrome-gtk-frame"{ ...})




• gtk.css




• gtkrc (gtk-2.0 folder / first line of style dark - background - ) :

style "dark"

{

    color["bg_color_dark"]  = "#303030"   #original was 3c3b37

    color["fg_color_dark"]  = "#dfdbd2"

    color["selected_fg_color_dark"] = "#ffffff"



fg[NORMAL]        = @fg_color_dark

fg[PRELIGHT]      = shade (1.15, @fg_color_dark)

fg[ACTIVE]    = @fg_color_dark

fg[SELECTED]      = @selected_fg_color_dark

fg[INSENSITIVE]   = shade (0.5, @fg_color_dark)



bg[NORMAL]        = @bg_color_dark

bg[ACTIVE]    = shade (0.8, @bg_color_dark)

bg[SELECTED]      = @selected_bg_color

bg[PRELIGHT]      = shade (1.0, "#4D4C48")

bg[INSENSITIVE]   = shade (0.85, @bg_color_dark)



text[NORMAL]      = @fg_color_dark

text[PRELIGHT]    = shade (1.15, @fg_color_dark)

text[SELECTED]    = @selected_fg_color_dark

text[ACTIVE]      = @fg_color_dark

text[INSENSITIVE] = mix (0.5, @bg_color, @bg_color_dark)

}

RESULT: