editing /boot/grub/menu.lst in the new BT4 release, I came upon the vga= line, and wasn't able to easily locate the syntax on the forums, so here we go (( special thanks to lifeforce4 of linuxquestions.org )) ::

VGA Resolution Codes for GRUB & Lilo
Code:
Width-Height-Depth	VGA Codes	HEX Codes
80x25 (TEXT)		3840		0xF00
80x50 (TEXT)		3841		0xF01
80x43 (TEXT)		3842		0xF02
80x28 (TEXT)		3843		0xF03
80x30 (TEXT)		3845		0xF05
80x34 (TEXT)		3846		0xF06
80x60 (TEXT)		3847		0xF07

320x200x8		816		0x330
320x200x16		782		0x30E
320x200x24		783		0x30F

320x240x8		820		0x334
320x240x16		821		0x335
320x240x24		822		0x336

320x400x8		817		0x331
320x400x16		818		0x332
320x400x24		819		0x333

640x400x8		768		0x300
640x400x16		829		0x33d
640x400x24		830		0x33e

640x480x8		769		0x301
640x480x16		785		0x311
640x480x24		786		0x312
Code:
Width-Height-Depth	VGA Codes	HEX Codes
768x480x8		866		0x362
768x480x16		???		????
768x480x24		???		????

800x600x8		771		0x303
800x600x16		788		0x314
800x600x24		789		0x315

1024x768x8		773		0x305
1024x768x16		791		0x317
1024x768x24		792		0x318

1280x800x8		864		0x360
1280x800x16		???		????
1280x800x24		865		0x361

1280x1024x8            775             0x307
1280x1024x16           794             0x31a
1280x1024x24           795             0x31b

1440x900x8		868		0x364
1440x900x16		???		????
1440x900x24		869		0x365

1600x1200x8            796             0x372
1600x1200x16           798             0x374
1600x1200x24           799             0x375
8bit = 256 colors
16bit = 65K colors
24bit = 16.7M colors