Palettes & Accent Ramps

Palettes & Accent Ramps

The dungeon runs in 6-bitplane EHB: 32 hardware colour registers, with 32–63 generated by hardware as half-intensity copies. The copper list that installs them is built in bcdfp (LAB_00BD).

One fixed core + a swappable accent ramp

Eight 32-word palettes exist across the game files. Comparing them shows a fixed core — indices 0, 16, 17, 18, 20–25 are byte-identical in every variant — while only indices 19 and 26–31 change. Those six changing indices (26–31) are the accent ramp.

File	Offset	idx 19	idx 26–31	Character
bcdfp	0x004194	033b→0020	0b30 0c40 0d51 0e62 0f73 0f84	orange / fire
bcdfq	0x0002c6	033b	0b60 0c70 0c80 0d90 0eb0 0fc0	gold
bcdfu	0x0003ec	033b	0432 0542 0653 0764 0875 0986	brown
bcdfu	0x00042c	033b	0223 0334 0445 0647 0858 0968	blue-grey
bcdfu	0x00046c	033b	0332 0443 0654 0987 0ba8 0eeb	stone / olive
bcdfu	0x0004ac	033b	0222 0333 0444 0555 0666 0777	neutral grey
bcdfu	0x0004ec	033b	0234 0345 0456 0678 089a 09ab	blue
bcdft (decompressed)	0x01e886	0fd0	0332 0443 0654 0987 0ba8 0eeb	stone / olive

The accent ramp varies per dungeon level

The table above is a census of copies. The authoritative ramp table lives in the decompressed bcdft image at S_1 +0x27B00 and has 12 entries of 12 bytes (6 words = COLOR26–31, one per dungeon level). The five bcdfu records are entries 0–4 duplicated into the epilogue overlay.

SetDungeonPalette(index) (S_1 +0x26900) writes the chosen ramp into the copper list at $510(A5) + 0x6A (= COLOR26).

Per-level defaults (13 words at bcdft S_2 +0x39E):

0,0,0,0, 1,2,2,2,2,2,2,3,3

Overrides: a map-square flag bit 31 forces ramp 4, and bcdfs action opcodes 0x1E/0x1F set it from the action record’s byte 0x06.

The tileset ↔ ramp correlation

Because the tileset file is also chosen per level, ramp and tileset correlate:

Tileset	Ramp	Levels
bcdfx	0 (tan) / 3 (grey)	1–4 / 12–13
bcdfy	1 (violet)	5
bcdfz	2 (bone/cream)	6–11

The verified sprite palette

For extraction, indices 0–25 come from bcdfp 0x4194 and indices 26–31 from the stone/olive ramp. The full verified table (12-bit → RGB, ×17 per nibble):

Idx	12-bit	RGB		Idx	12-bit	RGB
0	0x000	0,0,0		16	0x720	119,34,0
1	0xC86	204,136,102		17	0x952	153,85,34
2	0xF00	255,0,0		18	0xA53	170,85,51
3	0xB00	187,0,0		19	0x020	(varies)
4	0xD80	221,136,0		20	0x222	34,34,34
5	0xFE0	255,238,0		21	0x444	68,68,68
6	0x0F0	0,255,0		22	0x666	102,102,102
7	0x0B0	0,187,0		23	0x999	153,153,153
8	0x040	0,68,0		24	0xCCC	204,204,204
9	0x0DD	0,221,221		25	0xFFF	255,255,255
10	0x00F	0,0,255		26	0x332	accent 1
11	0x07C	0,119,204		27	0x443	accent 2
12	0xFD9	255,221,153		28	0x654	accent 3
13	0xEB8	238,187,136		29	0x987	accent 4
14	0xF0F	255,0,255		30	0xBA8	accent 5
15	0xE09	238,0,153		31	0xEEB	accent 6

Only maps that actually use indices 26–31 are sensitive to the ramp choice: map 7 (47% of pixels), map 8 (31%), map 6 (3%), map 11 (0.5%), map 4 (0.3%).

Title screen palettes (bcdfq)

Offset	Size	Used by
0x0266	16 × 16-bit	Raven logo (4bpp)
0x0286	32 × 16-bit	Title + Logo (6bpp)
0x02C6	32 × 16-bit	Plot text / intro (gold ramp)

A common pitfall

There is no separate “monster palette”. Monsters and walls necessarily share one EHB palette. The old bcdfu file offset 0x2C6 claim was wrong — that offset lands inside the library-name strings.