diff --git a/src/emu/emupal.h b/src/emu/emupal.h
index c75c4f7704b..0e1e8c57eb5 100644
--- a/src/emu/emupal.h
+++ b/src/emu/emupal.h
@@ -119,6 +119,9 @@
 #define PALETTE_FORMAT_BBGGGRRR raw_to_rgb_converter(1, &raw_to_rgb_converter::standard_rgb_decoder<3,3,2, 0,3,6>)
 #define PALETTE_FORMAT_RRRGGGBB raw_to_rgb_converter(1, &raw_to_rgb_converter::standard_rgb_decoder<3,3,2, 5,2,0>)
 
+// data-inverted 3-3-2 formats
+#define PALETTE_FORMAT_BBGGGRRR_inverted raw_to_rgb_converter(1, &raw_to_rgb_converter::inverted_rgb_decoder<3,3,2, 0,3,6>)
+
 // standard 2-2-2-2 formats
 #define PALETTE_FORMAT_BBGGRRII raw_to_rgb_converter(1, &raw_to_rgb_converter::BBGGRRII_decoder)
 
diff --git a/src/mame/drivers/liberate.c b/src/mame/drivers/liberate.c
index 24d30fab933..9e0b2b7d644 100644
--- a/src/mame/drivers/liberate.c
+++ b/src/mame/drivers/liberate.c
@@ -237,7 +237,7 @@ WRITE8_MEMBER(liberate_state::prosport_charram_w)
  *************************************/
 
 static ADDRESS_MAP_START( prosport_map, AS_PROGRAM, 8, liberate_state )
-	AM_RANGE(0x0200, 0x021f) AM_RAM_WRITE(prosport_paletteram_w) AM_SHARE("paletteram")
+	AM_RANGE(0x0200, 0x021f) AM_RAM_DEVWRITE("palette", palette_device, write) AM_SHARE("palette")
 	AM_RANGE(0x0000, 0x03ff) AM_MIRROR(0x2000) AM_RAM
 	AM_RANGE(0x0400, 0x07ff) AM_RAM_WRITE(prosport_bg_vram_w) AM_SHARE("bg_vram")
 	AM_RANGE(0x0800, 0x1fff) AM_READWRITE(prosport_charram_r,prosport_charram_w) //0x1e00-0x1fff isn't charram!
@@ -836,6 +836,7 @@ static MACHINE_CONFIG_START( prosport, liberate_state )
 
 	MCFG_GFXDECODE_ADD("gfxdecode", "palette", prosport)
 	MCFG_PALETTE_ADD("palette", 256)
+	MCFG_PALETTE_FORMAT(BBGGGRRR_inverted)
 
 	MCFG_VIDEO_START_OVERRIDE(liberate_state,prosport)
 
diff --git a/src/mame/includes/liberate.h b/src/mame/includes/liberate.h
index 442c5ca5b70..c86a926b090 100644
--- a/src/mame/includes/liberate.h
+++ b/src/mame/includes/liberate.h
@@ -5,7 +5,6 @@ class liberate_state : public driver_device
 public:
 	liberate_state(const machine_config &mconfig, device_type type, const char *tag)
 		: driver_device(mconfig, type, tag),
-		m_paletteram(*this, "paletteram"),
 		m_bg_vram(*this, "bg_vram"),
 		m_colorram(*this, "colorram"),
 		m_videoram(*this, "videoram"),
@@ -17,7 +16,6 @@ public:
 		m_palette(*this, "palette"),
 		m_decrypted_opcodes(*this, "decrypted_opcodes") { }
 
-	optional_shared_ptr<UINT8> m_paletteram;
 	optional_shared_ptr<UINT8> m_bg_vram; /* prosport */
 	required_shared_ptr<UINT8> m_colorram;
 	required_shared_ptr<UINT8> m_videoram;
@@ -59,7 +57,6 @@ public:
 	DECLARE_WRITE8_MEMBER(liberate_videoram_w);
 	DECLARE_WRITE8_MEMBER(liberate_colorram_w);
 	DECLARE_WRITE8_MEMBER(prosport_bg_vram_w);
-	DECLARE_WRITE8_MEMBER(prosport_paletteram_w);
 	DECLARE_DRIVER_INIT(yellowcb);
 	DECLARE_DRIVER_INIT(liberate);
 	DECLARE_DRIVER_INIT(prosport);
diff --git a/src/mame/video/liberate.c b/src/mame/video/liberate.c
index 0b49699cf2b..55011e47c58 100644
--- a/src/mame/video/liberate.c
+++ b/src/mame/video/liberate.c
@@ -243,14 +243,6 @@ VIDEO_START_MEMBER(liberate_state,prosport)
 
 /***************************************************************************/
 
-WRITE8_MEMBER(liberate_state::prosport_paletteram_w)
-{
-	m_paletteram[offset] = data;
-
-	/* RGB output is inverted */
-	m_palette->set_pen_color(offset, pal3bit(~data >> 0), pal3bit(~data >> 3), pal2bit(~data >> 6));
-}
-
 PALETTE_INIT_MEMBER(liberate_state,liberate)
 {
 	const UINT8 *color_prom = memregion("proms")->base();