StarCraft's effect images do not offer a colour. Two settings together produce one, though: put the image's drawing function on the redraw path and point its iscript at Warp Texture, 193. The colour then changes frame by frame after creation - one frame old is yellow, two frames is red, and so on.
So the way to use it is to show it only on the frame whose colour you want: create the unit in a corner of the map and bring it into view on that frame.
| Yellow, red, black | Always come out right. |
|---|---|
| White | Sometimes comes out grey after a StarCraft restart. |
| Anything else | They do appear in the sequence but are not stable. Test before relying on one. |
It cannot be used on a many-frame image: the Warp Texture script leaves no room for the image's own animation. The Marine's death image is the well-known one that will not load this way. It has to be a still, or something with few frames.
Purple is not on the list, and purple is made by mixing. Stack a red image at unit elevation 0 with a blue image that is CLOAKED at unit elevation 1 - or swap which is which. The cloak gives the translucency and the elevation decides which draws on top, so the two blend.
The same method generalises: any two of the achievable colours can be mixed. And the original example looks like a single frame only because its iscript was the Science Vessel turret's - a multi-frame script such as Maelstrom's animates.
A pure white canvas is the easiest case of all: create and remove a Warp Texture image every frame. If white is all you want, changing the image's drawing function to warp is enough without the script change.
Covering the screen in white as a flashbang is not recommended, though: in practice players dislike being blinded. The usual implementation goes the other way - drop the game brightness to 0 and show a black screen.
Two facts from these threads matter far beyond colour.
| A Door does not rotate | So an effect on a Door plays frame 0 and nothing else. Ticking “responds to combat” in its Special Ability flags fixes it - and this one tick is the whole reason people conclude that Doors cannot be used as effects. |
|---|---|
| The real Scanner Sweep is several images | The scan effect is the iscript drawing several scan images at offset positions. Copy one frame of it and you get a dot rather than the spreading @. Reproducing it means driving both the frames and the positions from triggers - and icecc ships the stock iscript as text, which is where to read the real sequence. |
The image's size cannot be changed. If the 210 rectangle is too big, the only option is to find a smaller image - this borrows StarCraft's own images, so the size is theirs.
Putting a picture on the map without spending a unitEffects on the screen itself