User Key: [HKEY_USERS\.DEFAULT\Control Panel\Colors]Value Name: BackgroundData Type: REG_SZ (String Value)Value Data: 0 0 0 - 255 255 255
However the monitor works at 60 hz while booting, so some colors will flick
Look at this:
http://www.emeraldcpu.com/loginui/login.html
and this:
http://virtualplastic.net/html/logo_scr.html#xpboot