Many thanks David, very good idea :)
I found trisquel-gtk-theme in synaptic with 3 gtk engines inside.
It definitely improved abrowser and the file manager, even claws though it's
still a bit ugly, but there might be dedicated themes.
On the other hand, synaptic didn't change, even after restarting/tweaking
lxappearance. but maybe it's like that in the live CD, I'll check again.
There's one package left that might be interesting (it has the cursor theme
for example. the package is called trisquel-desktop-common).
But the list of dependencies is very long.
I'll probably go through it and see what I want to keep.
