My English can be a bit awkward. If it is, that's because I'm Korean and my native language isn't English.
I think the searching system isn't working properly right now. I couldn't go through all the posts to see if anything similar is already written, but it seemed that there's no post that's discussing about the same matter.
Note : There's an unnecessary story below. Just jump to the conclusions if you wouldn't like to read it.
As Most of you'd already know, hallucinationed units ignore 'Give' triggers. This very often annoys us, especially when we've already made a bunch of triggers assuming that 'give' works for hallucinationed units. I first thought that was some kind of bug, but later I discovered some facts and thought it was intended,
One day, I was interested in experiments with hallucinations. I discovered that computers' hallucinationed ghosts can actually nuke somewhere with proper AI triggers, and I also found that hallucinationed queens can infest a damaged c-center. Furthermore, workers can gather resources from hallucinationed mineral fields/gas buildings until they disappear.
Then I did experiments with hallucinationed buildings, and got some interesting results. I gained control of a pre-placed hallucinationed add-on using real buildings, but the add-on didn't turn blue even though it said 'Hallucinationed'. I was a little confused, tried again, and got the same results. Then I tried another thing; I had a pre-placed add-on connected with a real building. As I launched the map, the add-on was blue. Then I lost control of it by lifting off the building it was connedted to. surprisingly, the add-on was still blue even though it wasn't mine then.
Thus I jumped into a conclusion: "Hallucinationed units look blue to, and only to its first owner." This fact made me think that using give triggers to hallucinationed units is banned intentionally.
That brought me another Idea. "Then, if I somehow manage to give control of my hallucinations to other players, wouldn't they look blue too?" So I worked on it. The good example of a way to change control between players without using 'Give' triggers or Mind Control(Hallucinations are immune to it) was add-ons, as mentioned above. Then I came up with an idea : "Dropships". Hallucinations can be loaded to dropships, and 'Give' triggers work for dropships regardless of what they have inside. I tested it, and the result was successful.
Conclusions:
To make someone else's hallucination that's blue, do the following:
1. Make a hallucination of yours. This hallucination can be any unit that can be loaded to a dropship.
2. Bring a dropship/shuttle/overlord nearby.
3. Load the hallucination to the unit of step2.
4. Give the unit of step2 to target player.
5. Unload the hallucination that will also have been given to target player from the unit of step2.
The hallucination will be blue even though it isn't yours.
I hope this gave you some help. See you later!
None.