still no joy trying to change "grey" product background size..

[dave204]

Does anyone know how to change height of the "grey" background in product descriptions in any category?
I am designing an online shop for a chicken meals take-away, and I want a pizza section where the menu consists of a single heading for each product, followed by a one or two-line description. And I don't want an horrible block of grey before the next product in the list. I have used Firefox, but that only gives me the name of the complete block - not the grey image. Is this in global CSS, and if so, where?
Many thanks in advance! Surely, someone has had to do the same??