non walkable graphic change

could there be a modification to the graphic (assuming it IS a graphic) that shows the areas Link can't walk on, but also shows the tile underneath? like, maybe instead of a solid square, there could be a box with a transparent center, or a half box, or something

this would help with setting transparent non-walkable combos (on layers) over tiles you don't want Link to walk on, like if you have a bush or something, and want/need Link to walk over the undercombo to move to the next screen... maybe an example quest would explain it better?

Hm. Or if transparencies are difficult, why not have every other pixel be transparent, and every other red, like the bottom of the screen is? (Except that's black, obviously.)