^ O.k. Teebin here we go.
Pressure treated lumber was green due to the copper in the CCA treating process. This process was discontinued over concerns about the arsenic component of CCA. This was replaced ACQ and CBA. These chemical packages did not contain arsenic. Unfortunately these treatments tended to corrode fasteners very quickly. We are now on the second generation of replacement treatments, mainly MCA and MCQ. These packages still have copper in them but it is micronized. This allows the copper to penetrate the wood without a carrier (solvent). In turn, this process leaves very little sign of being treated (re: minimal or no green tint).
The corrugated metal in the middle of the picture is the support for pouring a concrete slab. As there is electrical conduit, potable water and DWV (drain-waste-vent) lines installed I believe this will be some type of food service stand.