Pour exemple, la partie à modifier dans le gtkrc du thème 'Human' (Intrepid) situé dans '/usr/share/themes' :
engine "murrine"
{
animation = TRUE # FALSE = disabled, TRUE = enabled
colorize_scrollbar = TRUE # FALSE = disabled, TRUE = enabled
contrast = 1.05 # 0.8 for less contrast, more than 1.0 for more contrast on borders
glazestyle = 0 # 0 = flat highlight, 1 = curved highlight, 2 = concave style, 3 = top curved highlight, 4 = beryl highlight
gradient_shades = {1.07,1.05,1.04,1.01} # default: {1.1,1.0,1.0,1.1}
gradients = TRUE # FALSE = disabled, TRUE = enabled
highlight_ratio = 1.02 # set highlight amount for buttons or widgets
lightborder_ratio = 1.2 # sets lightborder amount for buttons or widgets
lightborderstyle = 0 # 0 = lightborder on top side, 1 = lightborder on all sides
listviewheaderstyle = 1 # 0 = flat, 1 = glassy, 2 = raised
listviewstyle = 1 # 0 = nothing, 1 = dotted
menubaritemstyle = 1 # 0 = menuitem look, 1 = button look
menubarstyle = 2 # 0 = flat, 1 = glassy, 2 = gradient, 3 = striped
menuitemstyle = 1 # 0 = flat, 1 = glassy, 2 = striped
menustyle = 0 # 0 = no vertical menu stripe, 1 = display vertical menu stripe
reliefstyle = 2 # 0 = flat, 1 = inset, 2 = shadow
rgba = TRUE # FALSE = disabled, TRUE = enabled
roundness = 0 # 0 = squared, 1 = old default, more will increase roundness
scrollbarstyle = 2 # 0 = nothing, 1 = circles, 2 = handles, 3 = diagonal stripes, 4 = diagonal stripes and handles, 5 = horizontal stripes, 6 = horizontal stripes and handles
sliderstyle = 1 # 0 = nothing added, 1 = handles
stepperstyle = 0 # 0 = standard, 1 = integrated stepper handles, 2 = unknown
#profile = NODOKA # engine profile options: CANDIDO, CLEARLOOKS, MIST, MURRINE, NODOKA
toolbarstyle = 0 # 0 = flat, 1 = glassy, 2 = gradient
window_opacity = 0.70
gradient_opacity = 0.99
}
RGBA = TRUE -> permet d'indiquer qu'on active la transparence (par défaut désactivée sur ce thème)
window_opacity = 0.70 -> une des options modifiées (ici l'opacité du fond est a 70%)
gradient_opacity = 0.99 ->une autre des options ajoutées
Après ca dépend des gouts (perso le fond de la fenêtre transparent c'est le seul élément que j'aime bien avoir semi-transparent).
