>I am calculating a percentage change for each of the records in a result set. I wanted to display a bar in the grid that would graphically show the number; as the user scrolls through the grid, it would be easy to see higher percentages.

I see. I think you may try to just create "progess bar" with shapes. There is also nice looking Progress Bar in Alexander Grigoriev library, which uses API only, but I'm not sure it would work with grids and perhaps it would be an overkill. I would say, try to create a simple shape based class.