win 7 can't paint combobox

Question

I have my program that paint the backcolor of a combobox column in a datagridview. I win xp everything works fine, but in win 7 the comboboxes have the gray color:

if you look the shot, you see that the combobox columns are grayed, but they must be yellow like the other columns.

if I use the old windows theme the grid is ok, but I wish use the new themes of win 7.

(i'm the developer, so I can change the code to paint the cell)

Answer 1

solved, use flat style for the combobox and the color is shown correctly