this may help if you don't want to duplicate palettes for two (or more) sprites that

use different palette sets, but you want them to use the same set in your project.



the palette loaded into nes vram is as follows (each letter is a byte):



    txxx mxxx mxxx mxxx

    mxxx mxxx mxxx mxxx



    t = universal background color

    m = mirror of t

    x = values that can be changed and will show durring rendering



the first row is for backgrounds and the second is for sprites. each sprite (8x8

pixel tile) has 4 bytes that are written to sprite oam. these 4 bytes contain this

data:



    0 - y position of the top sprite

    1 - the tile number of the sprite (index into pattern table)

    2 - attributes of the sprite (bits: 76543210)

        bits 0 and 1 tell the ppu what palette entry to render the sprite with so:

            xxxxxx00 = 1st sprite palette

            xxxxxx01 = 2nd

            xxxxxx10 = 3rd

            xxxxxx11 = 4th

        the 'x' bits do other stuff, but dont pertain to palettes

    3 - x position of left of sprite



now trace the value in ram (probably somewhere in $0200-$02FF, though not

always) for the attribute byte of the sprite you wanna change. set a breakpoint

for when that address is written to so you can see where the game sets that value.

now change the value that is written to that address to reflect which palette you

want to be used durring rendering of that sprite. be sure all the 'x' bits are the same

in your new value or you will get some strange effects.



the 4 bytes will always be in the order listed above because more then likely the

game will use sprite dma to transfer all the values into sprite oam. so if the data

is stored at $0200 it will be in this order:



    $0200 = sprite0_Y

    $0201 = sprite0_T

    $0202 = sprite0_A

    $0203 = sprite0_X

    $0204 = sprite1_Y

    $0205 = sprite1_T

    $0206 = sprite1_A

    $0207 = sprite1_X

    ...etc...



hope this helps.