JoW88

I have an image saved as a png. The image has a transparent background.

I'd like to upload the image as the background on a section of my site (as an image with a transparent background). 

Whenever I try and add the image to the background, the transparency is lost and the used-to-be-transparent background turns black (the site section colour is blue).

Reducing the overlay opacity doesn't help and increasing it creates a blue wash over the image as well. 

I could add a blue background to the image prior to uploading it except I'm trying to get a film grain effect on the image only, not the whole background. Hence the need for transparency. 

Anyone know how to get around this? 

Thanks