Name the unused timer warning palette, fix a stale address

gUnknown_086B0864 is not the slow palette - gTimerWarningPalette_Slow
already exists two labels down. All three differ only in colour 3, red
for _Fast and yellow for _Slow, and white here, so it is the white
member of the same set. Nothing points at it; the code alternates _Fast
and _Slow against gDefaultTimerPalette, which lives in rom_1.s.

gUnknown_086AACE6 carried an address comment of 0x086AACEC. The name is
the correct one: at 0x6AACE6 the count reads 1 and the entry matches
what is emitted, where at 0x6AACEC it would read 4252, and with the
right address the record ends exactly where the next label starts.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

data/rom_2.s

@@ -4370,7 +4370,7 @@ gUnknown_086AACDE:: @ 0x086AACDE
 .2byte 1
     packed_sprite_oam x=-0x10, y=0xf0, spriteSize=SPRITE_SIZE_32x32, tileNum=0x18, paletteNum=0x1
 
-gUnknown_086AACE6:: @ 0x086AACEC
+gUnknown_086AACE6:: @ 0x086AACE6
 .2byte 1
     packed_sprite_oam x=-0x10, y=0xf0, spriteSize=SPRITE_SIZE_32x32, tileNum=0x9c, paletteNum=0x1
 
@@ -8496,8 +8496,11 @@ gFieldInitFuncs:: @ 0x086B085C
 	.4byte MainGameFrameUpdate
 	.4byte BonusFieldFrameUpdate
 
-gUnknown_086B0864:: @ 0x086B0864
-    .incbin "graphics/stage/main/timer_warning_0.gbapal.bin"
+@ The white member of the timer warning set: identical to _Fast and _Slow except for
+@ colour 3, which is white where they are red and yellow. Nothing in the ROM points at
+@ it - the code alternates _Fast and _Slow against gDefaultTimerPalette instead.
+gTimerWarningPalette_White:: @ 0x086B0864
+    .incbin "graphics/stage/main/timer_warning_white.gbapal.bin"
 
 gTimerWarningPalette_Fast:: @ 0x086B0884
 	.incbin "graphics/stage/main/timer_warning_fast.gbapal"