jsilveira,
Not a stupid question at all. Create a user-defined chart type with whatever you desire. First, create your column chart with the colors you like. Then select the chart, choose Chart Type, Custom Types tab, click User-defined button, click Add... then give your chart a name and description and click OK.
Then if you want to use this chart again select it from the Custom Types tab, User-defined list. If you want this to be your default chart then click Set as default.
Hope this helps.