Changing header overlay on back pages

Can’t figure out how to change the overlay over the image in the header on all back pages (everything except for front page).

I scoured through the CSS and couldn’t find it.

Here’s an example -

When you first get to the page, you can see an image in the header with an overlay of #000000.

When you scroll down, the color changes to blue. I’m trying to change the #000000 overlay to a similar blue instead.

Hello there,

You should be able to achieve this with custom css code below:

.overlay {
    background-color: rgba(59,119,156,0.9);

You can apply the code with this plugin

Following link can help you to generate desired RGBA value from HEX value

All the Best!