SMW Memory Map
|$7E0682||19 bytes||Palettes||Used for uploading palettes dynamically. SMW uses this in the lightning/Magikoopa/Big Boo Boss palette effects. $7E:0682 holds the amount of bytes to transfer, $7E:0683 holds the color number (stored to SNES register $2121), the bytes afterwards hold the actual color values transferred to the CGRAM. Further, this table may be indexed by $7E:0681 to add more color destinations; it's terminated by a #$00. The format is the same as before, just at the new location.
This table doesn't actually have to end at $7E:0694, but SMW never goes beyond this. As such, the area after this address is listed as "empty".