One of the things that is just a tad weird about CHS is the grid selection style. To me, it seems like the opposite of what I expect, like looking at a negative photograph.
When you click on a "cell" the color of the selected cell doesn't change at all (which is counter intuitive). Instead the whole row highlights, except for the clicked cell. I like the whole row highlighting, but it would feel better if the selected cell was highlighted some way also, perhaps a light yellow background just to distinguish it from the non selected cells.
Or better yet, let the users choose the colors for all that stuff. What do you say?