How to make the header of a page transparent even when there's a slider right under it.

1. I made a slideshow 7.1 and I tried setting my header to "dynamic" but the header is not transparent and I think it's because I have a slideshow directly under it. How can I solve this? I really want the transparent header

2. The text displaying on the slideshow are not very readable on each slides. I'm looking for a way to reduce the transparency of each image on each slides and add a black overlay to make the white text visible.

#1. This is possible to achieve this

#2. How about adding a dark overlay over image?

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