To use the palette for the pointer, we would have to look to see if we can find and change the sprite attributes. I found that the sprites for this game are within the $0700-$07FF range in RAM. As we can see, there are a bunch of "02" values found within that range, in an organized manner (because each sprite consists of four values, including its X and Y position values, the graphical tile used for the sprite, and which part of the palette is used for it). With the PPU Viewer, it can be seen that the third quarter of the sprite palette is what the "G" and "O" uses. Considering values/identifiers of 00, 01, 02, and 03, we can break the sprite palette up into groups of four values each.
So, I used the first "02" attribute value that I could see within the sprites range, since the attribute for the sprite is what we're trying to change, at $0706 in RAM, to set a conditional write breakpoint. I assumed the value of "02" that we're looking for would be loaded into the Accumulator register, so my condition is "A==#02".
When transitioning to the Game Over screen, the debugger froze at $9A62 in RAM. When scrolling up, a line of code where a load of a value of "02" is found, unlike previously when the load wasn't found in the nearby code, and was actually in a different area that we located by referring to the stack.
$9A60 in RAM is 0x1A70 in the ROM, so let's look there.
Since the pointer uses the first quarter of the sprite palette, let's try to change the 02
in the ROM file.
Following this, I reloaded a save state that I made on the fourth level and lost again. After transitioning to the Game Over screen again, the "G" and "O" sprites appeared different. Looking closely, the insides of the letters were now pink instead of grey, and the outer borders were light blue instead of light green. Looking within the $0700-$07FF range in RAM, the values that were originally 02 are now all 00. Therefore, it is reasonable to conclude that the change we intended to make was successful.
As you pointed out, the third quarter of the sprite palette (02) was different depending on which level you got a Game Over on. However, it seemed that the first quarter of the sprite palette (00) was always the same. So, hopefully this is the change that you wanted.
Like before, I could be missing something. Hopefully not. Maybe I need to eat something...
Best of luck with your project!