How Do I Make The Header Of My Shopify Page Have Opacity I Want It At .6 Like The Middle Text Box

[UrbanPad]

when I say header I am referring to the place that it says UrbanPad, Products, etc 

I want it to match the middle, i was able to do this before the new shopify update but now the code is gone 

[ZenoPageBuilder]

Hello @UrbanPad 👋

Inside Shopify Admin, you can go to Edit theme code, open file base.css and add this code at the bottom

.header-wrapper {
    background-color: #FFFFFF99;
}

The result