Help with GTK3 Theming

[jEsuSdA 8)]

Hello!

I'm using Zukitwo-Colors GTK3/GTK2 theme [1]. This is a nice theme cause 
looks great with gtk2 and gtk3 applications and made the XFCE desktop 
looks nice!

This theme is based on Zukitwo theme [2], but all them have the same 
problem: some applets looks ugly.

As you can see in the next screenshot, the "cpu load" aplet (on top 
panel) has 2 ugly grey borders instead taking the background panel color.

The "disk free space" applet  (bottom right) just does not show the 
barrs, so it is unusable.

http://www.pasteall.org/pic/show.php?id=32682

I want to fix these small problems, but I don't know how.
Could you help me?

What kind of widgets are these?
how can I give them the right styles?

I have some experience retouching gtk2 and gtk3 themes, but I can not 
identify these widgets.

Thank you!


[1] http://gnome-look.org/content/show.php/Zukitwo-Colors?content=146290
[2] http://gnome-look.org/content/show.php/Zukitwo?content=140562