[Animated Rain Tutorial]

This style was too cool dude!!! This is what I made!

[Exploding planets]

Hey dudes this Exploding Planets style is AWESOME!!!! I am totally new to Paint.NET and am now trying to learn things here. I tried it out and it worked all right. I made a blue exploding planet just like the one shown in the example. But when I saved it and reopened it, I saw that the image was totally white. Can any of you tell me why this happened and how can I correct this?