Instead of applying to the Look & Feel section, just add the Text/Graphic question type to the top of the block, and you can duplicate it for the top of the pages within that block as necessary.

When we have needed to do something like this, we actually create a text/graphic question type at the "top" of the block, and turn off any logo on the survey itself. (This also allows for display logic to determine which branding should be used and/or for the brand name to change dynamically, if there is a brand-related indicator in the contact file to inform this.)
What this won't do is change the colors in the survey from block to correspond with the logo, if that is a need. Not sure if someone else has a suggestion in that area.