gkleds can be themed by making the following image and placing it 
into a "gkleds" subdirectory of a theme: 
- leds.png : contains all subimages which makes up the LEDs.

The image may be of type png, xpm or jpeg.

This image consists of any number of vertically stacked subimages. 
The subimages must be the same width and height. If not, then
they will be displayed wrongly. Transparency is supported(and encouraged).

You must also tell gkleds how many subimages there are(again, they will
be displayed wrongly if you don't). This is done in the gkrellmrc file:
set_integer gkleds_num_img = n

If you don't set "gkleds_num_img", then the default hardcoded define "GKLEDS_NUM_IMG"
will be used.

If your "gkleds_num_img" is less then "GKLEDS_NUM_IMG"(or some other themes 
"gkleds_num_img") and a theme change occures, the following will happen: 
If a previously selected subimage has an index(into leds.png) higher than 
your "gkleds_num_img", then that subimage will be set to "none".