Exposure correction of outdoor photo

"Look at the photograph I have sent you. It was taken on a bright day, but it doesn't look like that — in fact, it looks quite dark, like an evening shot. I have tried resources that allow you to lighten the picture. Problem is that when I lighten it, the sky becomes white and the parachute colours change. Now, I don't want that to happen. I want the sky to stay the way it is, and I want the parachute colours to remain exactly the same. Help!"