Grid Edit Formatting

I have a data set with many components which consists of about 26 columns to be edit in a grid edit. Right now it looks like 1 very long string of columns going across and doesn't create the best user experience. The 26 columns have subsets which I would like to visually differentiate from each other. One idea was to color each subset of columns, but I was told that the only way to do that was Image On Load and that was not an advisable technique. Anyone have any other ideas to help break up this really wide grid edit to be more user friendly?

Steven