Open Photoshop and make your logo.
Choose Save for web...
Select PNG-8 > 8 colors.
Done.
Don't use gradient or light efects on your logo, just solid collors.
After convert the png to mr, use this program to insert your logo.mr into the ip.bin.
Link:
Logo Inserter
Choose your ip.bin
Choose your logo.mr
Confirm
Choose your ip.bin again
And insted of your logo.mr, choose the same ip.bin.
It will open a preview window with your logo placed on the Sega screen.
If you want to make a logo with a white background, use this collor on the Photoshop.
C0C0C0
I know, it's gray, but you'll see when you open the preview screen in the Logo inserter.