How to change individual tile palettes in Super Mario Bros. (NES)

[Ladondorf]

In the original Super Mario Bros, the bridge uses the Scoreboard palette and the axe uses the Coin palette. How do I make it so they both use the Brick palette instead?


Here's what I want the level to look like once it's completed.




Here's how it currently looks.




Here are the palettes.



The bottom one is the hack's Castle Palette, the middle one is the original Castle Palette, and the top one is the Overworld Palette, for clarity's sake.


Help is much appreciated!

[Pluvius]

http://wiki.nesdev.com/w/index.php/PPU_attribute_tables

You'll have to change whatever ROM data is used to set the attribute tables for that screen.  If I'm counting correctly (and assuming that empty areas use palette 0), you'll have to change whatever is written to PPU addresses $27E9-27FE (the bridge) from $#0A (00001010) to $#05 (00000101), and change $27E7 (the axe) from $#53 (01010011) to $#51 (01010001).  (The PPU addresses might be $23xx depending on which nametable that room is written to.)