https://developer.valvesoftware.com/wiki/Info_paint_sprayer - Paint Droppers

https://developer.valvesoftware.com/wiki/Paint_sphere - Pre-painted surface

thank you for helping to create the sprayers, but for some reason I don’t have the texture of the paint, help with that too please.

Texture? you don't apply the texture directly???

https://developer.valvesoftware.com/wiki/Paint_sphere - Pre-painted surfaces!
"It paints brush entities inside the sphere. "

OH RIGHT also!

"Gel needs to have Paint in Map set to True in worldspawn before applying on surfaces. Maps that do not use gel can save significant resources by avoiding gel code."

Make sure not to forgot this I've done it a few times once!

I managed to make a sprayer with everything I needed, but I need the gel to immediately be on the floor when loading the card (that is, I need to cover almost the entire floor of the test chamber with gel), but if I fill every cell with gel, the card will not be optimized + the gel does not fill the cell completely (which means that while running on the gel a person will often lose some of their speed). In short, now I have a question about how to fill the entire floor with gel with a small number of objects.

To help with performance, one thing you can do is enable the "silent" option on the sprayer. It's wrongly named, in addition to stopping sounds it also prevents the actual gel visuals from appearing, so it just paints the brushes. To cover more space, one thing you could do is parent the sprayer to something like a func_movelinear, so it gets moved across the surface painting as it goes. A really big paint_sphere might work better though. If you're really worried, just make sure you Kill the ents after they're done painting.