Its funny how the title screen boots up green on a sears intellivision. Havent tried on an actual system just had done it before in jzintv with the sears bios
There's more than one game with that issue. Has to do with the different timing of the Sears EXEC. The phrases "Mattel Electronics presents" and "Copr @ 1984 Mattel" that get displayed on the Mattel title screen are in GROM, and is only accessible during vertical retrace. The Mattel title screen code therefore waits until vertical retrace so it can copy that to the title screen. The Sears EXEC skips that step, for reasons that I hope are obvious.
Some games that set a different title screen color do so in the code that runs immediately after the title screen is constructed. With the Mattel EXEC, there's still a little time left in the vertical retrace, so the program can write to the STIC to set the display color. With the Sears EXEC, it's not in sync with the vertical retrace at that point, and so the write that sets the screen color gets dropped.
I committed exactly this error in the title screen I wrote for Chad's Intellicart.
And, technically, the default title screen color is "brown," although the Intellivision's brown is a very, very greenish brown.