How to give globally transparency to the Default Header with the default titles?

Follow the steps below:

1. Go Appearance > Customize > Default Header and set the transparency you prefer for your default header.
2. Go Theme Options > Page Options and upload the background image you prefer for the title area. Do the same in the Theme Options > Blog Options for all the archive pages (categories, tags etc).
3. Finally add the code below in Theme Options > CSS Options

#grve-body.single-post #grve-header,
#grve-body.archive #grve-header {
    background-color: transparent;
}


#grve-body.single-post #grve-post-title,
#grve-body.archive #grve-page-title {
    margin-top: -90px; /* Give your Header's Height */
    padding-top: 90px; /* Give your Header's Height */
}
#grve-header[data-topbar='yes'] #grve-inner-header {
 position: absolute;
}

Then you will have a transparency header globally :)