Changing Gel Colours
I unfortunately return with sour news. As stated I emailed Valve, specifically Dave Kircher. He then seems to have passed on the message to Pongthep Charnchaichujit who has confirmed to me that the code IS in the game itself:
So at this point I and everyone else has 3 options. The first is to simply use purple paint. The second is to wait and hope Valve do eventually release code access. The third is to have the paint blobs that you want but not have the paint land on anything. I.e, the paint falls into the sludge in the underground or just falls into the chasm in the modern facility. This means your effect can still be applied to objects/cubes. The fourth is to wait until I or someone else figures out a way. Considering the importance of the mechanic to both the storyline and central gameplay mechanic we wish to add I will have to continue working on this to try and figure it out.
If someone comes up with a solution before I do, please post it up here. Massive credits will be given.
Lastly, thanks to everyone who has helped me with advice and notes for where it could be. Goodluck out there gentlemen.
I don't know if this has been posted already, but in addition to unused paint type "1" which is purple, there's type "5" (dark blue) and "6" (black)
When I try to shoot a portal at purple, nothing happens. When I try to shoot a portal at dark blue or black, my game crashes.
OMFG! No this had not been posted and I didn't think Valve had any other paint in the system! The only reason I found the abandoned sticky purple paint was because the number 1 was not used, it jumped from 0 to 2!
Sir, your finding is astronomically important to me! We now however have to hope that there is a way to add a blob texture. We guessed correctly that the purple paint was 'stick' so we just did that as the end of the name of the texture and it worked. What the hell could these be!?
If you'll notice however, there is no splash particle effect with these paints. They do not exist at all. However this is less important then a correctly coloured splat!
I don't want to rush back to Valve and annoy them with this the day after I asked them for help with the other question. It is likely that these paints were other abandoned game mechanics. If this is the case I wouldn't hold my breath on getting the name of the texture we need to add as it would reveal the mechanic, something they are probably thinking about using later.
Everytime I give up on this someone finds something to spur me on. The hunt is back on in less then 12 hours after it ended, gentlemen! We must find the blob names to make those 2 gels work! HUZZAH!
- Fuck, we'll have to find a solution. It's either finding a way to block portals and add a blob texture or attempting to somehow automatically colour correct a texture that doesn't exist. I haven't given up yet... again.
I believe I know why firing at those 2 would crash from looking through the code in the binaries, it appears they don't have the proper handlers for Portal placement that they all inherit because the white gel needs it so it crashes. If it was giving verbose error messages I assume this would be a pure virtual function call, I'll check with a debugger when I get the chance. If this is the case there is no way to fix it without patching the game exe or modifying it in memory as it crashes even if you fire at it on a metal surface.
Ah fuck. I thought walropodes might mean just when it was on a standard portable surface which would have still allowed it to be used without heavy modification.
Omni, can you tell what the name of the material is supposed to be, i.e, portal, stick, bounce, speed for the blob materials for either colour, or has that not been properly determined either? (If it's not determined I take it there's no way to add the texture it requires.)
Also, where are these binaries?
It isn't defined. There's a chance naming it with no prefix (but still keeping the underscore) may work if the engine is just concatenating the paint type name with the material suffix.
i know this is 4 years later, but valve was lying- you can change the splat color with these console commands:
[speed/portal/bounce]_paint_color [red amount, 255 max] [green amount, 255 max][blue amount, 255 max] [transperancy, 255 is the fully opaque default.]
now you just need to know how to re-skin the blobs themselves and your good. 
===========================
Im blue, a Clean Christian Furry with Autism.
[speed/portal/bounce]_paint_color [red amount, 255 max] [green amount, 255 max][blue amount, 255 max] [transperancy, 255 is the fully opaque default.]
now you just need to know how to re-skin the blobs themselves and your good.
Several people have already used this, look at (Hammer) maps with Adhesion or Reflection or Adhesion or whatever gel in them.
But if you have discovered this thread among the ruins of civilization, welcome! And remember, in singleplayer you need to reload the map after applying the console commands, unless you want them to only affect the screen effect when the player is painted. Testing is the future, and the future starts with you!
* If the developer console no longer applies in the future, God help you.