Patching extra functionality into <gamemd.exe>

[Tratos]

For the electrobolt colours, would it be difficult to do something like this:

EBoltColor1=0,house,0
EBoltColor2=house,house,house
EBoltColor3=house+100,transparent,house-100

or is that too difficult/inefficient?

Uh, rgb doesn't work like that, what you have suggested would probably cause numerous crashes.
The values are specified as RGB so the first value is how much red there is, second is green and third blue. Like mixing paint together you can have any colour you like from using different amounts.
Specifiying something like;

EBoltColor3=100,100,0

would mean 100 red, 100 green and 0 blue. You would get a yellow colour. Something like;

EBoltColor3=house+100,transparent,house-100

would mean that the first value (red) would be your house colour plus 100 red. But, if your house colour is green that makes it green + 100 red.
green + red doesn't make red it makes yellow and im not sure how the game would handle this.

@Pd: I think that is a very good idea but i still think having a single term for the two variations would be much easier (modder wise, i have no idea if it would be easier for you) and avoid such confusion as above. i.e.

EBoltColor2=transparent
EBoltColor3=house