1. Locate the folder where your background is saved.
If you're on Win7 64-bit or Vista 64-bit, then it is here: C:\Program Files (x86)\Stardock\ObjectDock\Backgrounds\Non-Tabbed\Vector Cell. Otherwise, it's here: C:\Program Files\Stardock\ObjectDock\Backgrounds\Non-Tabbed\Vector Cell.
2. Download these docks: https://www.wincustomize.com/skins.aspx?skinid=16254&libid=29
3. Unzip the folder for the docks you just downloaded. Copy the blank.png file from the folder into your Vector Cell folder.
4. Open the background.ini file found in the Vector Cell folder. Copy and paste these lines to the top of the code (under the name):
[Tile]
Image = blank.png
ResizeIconByPercent = 75
OffsetIconByPercentX = 50
OffsetIconByPercentY = 50
5. Save the background.ini file then reapply Vector Cell through your ObjectDock settings.