Browsers changing my sig

So in Chrome my sig shows up the right way. The background is the same color as the sythe background so my sig background looks transparent. But in Firefox my sig has a darker blue for a background. Can anyone help me out?

 

The easiest option and most effective would be to make the background transparent.

 

i didn't think transparency would work with a sig? I thought by default it would make the background white. What do I have to save it as, .png?

 

Yes, make sure you save it as .png, or it won't turn out as expected.

 

Note - to fix the "default" color as white, there's an option when you select "New." Change that to transparent and you're all good. If that doesn't work, rasterize the layer or add a transparency layer depending on your program and ctrl+a & delete.
Hope that helped, post w/ any more questions.
Also, he's right. .png can handle transparency and are the best at it.