Adding onto the previous answer with gimp. When you have finally got your background transparent (Try changing the threshhold of your fuzzy select to remove the background) save that as a png or another file that does support transparency. You will always have that as is then.
Safest way when you want to make the background a colour you like, add another layer and make it the colour you like - dropping the layer to the bottom. Then you can be sure it will fill in all of the area that is transparent.
If you don't like that colour layer, delete the layer and add another and do it all over again until you get the colour you like.
NEVER fill in the area that you have just got rid of from your original picture unless you are really sure what you want and that it will work.
Feathering cannot be too large either as you will end up with a white border around your image. [small for small images and larger for large images]
Safest way when you want to make the background a colour you like, add another layer and make it the colour you like - dropping the layer to the bottom. Then you can be sure it will fill in all of the area that is transparent.
If you don't like that colour layer, delete the layer and add another and do it all over again until you get the colour you like.
NEVER fill in the area that you have just got rid of from your original picture unless you are really sure what you want and that it will work.
Feathering cannot be too large either as you will end up with a white border around your image. [small for small images and larger for large images]
