Database design question

I manage a product line and I am working on an application for myself to manage price lists and inventory. I have a table of "Items", this table currently looks something like this.

ItemID     ItemNumber     ItemDescription     ListPrice     LastUpdate     SizeID     ColorID     ShapeID

So this item can have several properties or fit into several categories. For example, this item might be "Blue". It might be "Long". It might be "Square". I am struggling on the design if the database that will allow me to grow as new products are added and new Categories arise without having the database built around these categories.

This is what I would like my items table to look like. And then if a new category is required I can simply add to a list of categories and apply items to categories or categories to items.

ItemID     ItemNumber     ItemDescription     ListPrice     LastUpdate

Any suggestions or direction would be very helpful...