Gradient overlay on row background image

Hi
I have a background image on the main row of my home page (using the Row Wrapper section) and want to put a gradient overlay on it (so that text can be read more easily). I'm having difficulty using the Overlay Styles section to create this. Sometimes I can create a gradient but it replaces the image; sometimes I cannot create the overlay at all. Often the edit boxes for the gradient colors cannot be accessed. I cannot work out how to use this section. Is there any tutorial for using the Overlay Styles section?
Thanks.

Hi
you can setup the 1st color, then the last color become active and you can fill it.
to use gradients here, the only solution is to use "rgba" colors, like this : rgba(255,255,255,0.3)
you can write this in the color field

CEd

That works! Thank you.