How to add colour to a cell?

em_z

Hi, I'm trying to create a product options table (you know the kind with free/standard/premium options)... and want to highlight included, optional and not included elements in green, amber and red. I can't find a way to set cell colour etc, and would appreciate some help please. I'm not technical, so please be kind (and apologies if this has been answered before - I can't find a thread!)
Thanks.