Hi Noa,

Yes, you can change the colors of selected columns in a stacked column chart. Here's how:

1. Select the chart by clicking on it.
2. Click on the column you want to change the color of. This will select the entire series.
3. Right-click on the selected series and choose "Format Data Series" from the drop-down menu.
4. In the Format Data Series pane that appears on the right-hand side of the screen, click on the "Fill & Line" tab.
5. Under "Fill," click on the "Solid fill" option.
6. Choose the color you want to use for that series by clicking on the color swatch or entering the RGB values.
7. Click "Close" to apply the color change.

Repeat these steps for each series you want to change the color of. By default, Excel will use a different color for each series, so you shouldn't have to worry about the colors overlapping.