Found the below on reddit
http://www.reddit.com/r/jailbreak/comments/1wfqw6/request_change_respring_screen/
I found out something today that could lead to this being a possibility, Turn on "Invert Colours" (i'm Australian so i spell colour differently) in the Settings app and then respring your device and you should notice that the respring boot logo is inverted!
So if Apple can change the boot logo with a simple flick-of-a-switch then why cant a tweak be made that does the same thing but doesn't invert the colour of the whole iOS?
If you reboot your device then it starts off as the default boot logo but half way through the boot process it enables Invert Colours which causes the Boot Logo to invert (as it should)
P.S. It would be possible for iOS to boot-up with a custom boot logo straight away but only if a bootrom exploit was found for that device! (If i stated something wrong then please correct me)