Datagrid with WINFORMS

Hi I have a datagrid in which I populate a combo box dynamically in one of the columns. Now when a combo box is populated with data in it and I click the combo box one of the cell(in the data grid) in the same row as the combo box, should be populated with a color, that is the color of a cell should change. Now the same thing should happen in another row that is when the combo box of another cell is clicked a cell in the same row as the second combo box should be populated with another color. I have tried this in Win Forms which is my requirement and have not got any success. As of now am populating the color in the cell by placing a text box and changing the color which is not my requirement and the problem that I am facing with this is that as soon as the color is changed in the text box then I am not able to work with other columns where the combo box is placed dynamically. Please help. Regards Tellie George