Well, I don't know about the program Fresh Paint, but you can blend a ton of colours to make up the sky; which can influence other objects in your scene. I'm not a good artist, but I think this picture can help you a bit. [link]
Try to use a lot of colors. Instead of picking one color for the sky, pick a bunch, and they all don't have to be blue. Look at a lot of pictures that you like and sometimes practise thought painting of a reference, it gives you a good idea of how things look in real. Play with textures and several different brushes, simply don't limit yourself. You learn a lot through experimenting.