QUOTE
I'm not sure re-flashing my chip every five minutes until I get it right is a good idea
iND-BIOS.5003 and X2.5035 will both work for you, and both can be reconfigured without reflashing, because they read their boot config from a text file on your hard drive - so you can tweak the colours to your heart's content, but still only flash once.

iND-BIOS.5003 works on 1.0-1.5 Xboxes, X2.5035 comes in two flavours - one for 1.0-1.5, and one for 1.6 Xboxes.