Colour of slide text background

Hi, can You please tell me how to set colour of slide text background, also slide header background. Thanks in advance.

Put:

.hero-carousel article .contents{
background:...
}

at bottom of template_css.css, use !important flag if needed

I did that, but it changes wrong background. It added another backround behind grey. I did screenshot of it. I need to change this grey background behind letters. Upper in one colour, downer in another.

Use:

.hero-carousel article .contents *{
background:...
}

Thanks, it works, but now both are same colours and not transparent as original.

What about something like:

background:rgba(255,255,255,0.5);