Could they make "pressure stained" wood?

[Stephen Tashiro]

Would it be possible to manufacture "pressure stained wood"? - wood where a stain was applied throughout the piece of lumber instead of just near the surface?

I don't know how the pressure is applied to "pressure treated" lumber. I suppose they put it in a pressurized container. I wonder what amount of pressures is applied. Could the same procedure be used to force stain into the boards instead of preservative chemicals?

[Dan Hintz]

I know they make plastic injected wood (not just dye) that gives a solid color throughout... I'd have to look up the address.

[Jeff Books]

Pressure treated wood is processed in huge autoclaves where steam pressure forces the treatment in. Frequently the wood is wet enough that cutting it releases water. If you look at a bundle of pressure treated 2x4s the outside boards are darker than the ones in the center. I suspect you would have similar issues with dying wood that way.
The plastic wood now used in decks is wood chips added to molten plastic in an extruder and shaped into a board through a die and quenching bath. Pigments can be added as well.

[Lee Schierer]

Most stains are made up of pigments which are particles of material that normally stay on the surface of the wood because they can't pass through the pores or cell walls. Forcing particles through cell walls is a lot harder than pushng through a liquid. Presure treated lumber is done under vacuum followed by high pressure, with the cycle being repeated in some cases.

[Larry Edgerton]

Google Thermowood. This process is interesting, its a high heat vacuum drying process that does some amazing changes to the wood according to the claims. I have not worked with it yet personally.

One of the changes is that the color of the wood changes all the way through.

Not what you were after but has possibilities along the same lines.