How can I change the default folder icon? changing the icon via properties only applies to the current selected folder, but i want to change all folder icons... just don't know how.

here's a snapshot of my dolphin, with the default oxygen folder icon:


and this is the icon i want:


Pd. i'm using kde4.2 beta

You can modify the oxygen icon theme for that. Navigate to /usr/share/icons/oxygen//places and change the "folder.png" image. To do from konsole (assuming this new icon is on your Desktop).
Please make sure to scale this image to the respective size before copying it. ie, resize this image to 32 x 32 pixels before copying it to the 32x32 folder.
For making changes to the icon folder, you need to launch dolphin as root. And with that, you should be very careful while using it as root (which gives you write access to all system files)

thanks for the repply
but it didn't work

after looking for anothes folder-like icon (it had to be somewhere over the /usr/share/icons/oxygen, that was for sure), I found the "/usr/share/icons/oxygen/#x#/mimetypes/inode-directory.png" file, which i changed and did the trick