Eltel

Hi all. Firstly it's great to see a active old Xbox community. I am a new member so please be patient I am a retro collector and I have 3 old Xbox consoles. X2 are tsop modded with the wincore 256 chip.. and I have one v1.6 that I am awaiting to chip. Anyway.. one of the 1.5's I bought a long time ago and when it booted it no longer displayed the green Microsoft boot screen before the xecutor logo.. and the logo was orange. I flashed the bios chip with a bios off the hexen disk everything works.. but now I get the green boot screen and normal xecutor flash screen before my console launches.. So guess my question is. was this a custom bios and are they difficult to change? Many thanks