[Unsolved] Where can I find this mouse click and drag box section?

[Zocom7]

What I mean is that SCII has a background colored shader in the mouse click and drag box, but I can't find the coding or the UI using the MPQ Editor. I need to read it to understand what it contains.

I once discussed about this in another forum and no modder or developer was able to implement this in a recent C&C game (not even myself). I have seen implementations like this in a Half-Life 2 RTS mod and in Starcraft II.

 

[Dr Super Good]

It is either a game constant (check the data) or it is hard coded into SC2. I would not imagine any data for fill colour of the selection box being inside the MPQ.