When new, definite plastic sheen. Even brick and tiles aren’t dead matte, possibly because the semi gloss is less prone to scratching in packing and shipping , tougher?
imho, one could paint to hide the plastic look.
i rarely re paint pola items, mostly to avoid additional maintenance. Here at altitude, uv is tough on paint and flat coating. And idont even leave my stuff out for long periods, and try to shade things, mostly ( some items can warp badly in hot mid summer sun).
But, i have painted partially and /or completely , as some models , mostly US, just have odd coloring/combinations, or, are just in need, such as contrasting wainscoting , bright white window mullions but not the window frames, etc. Not unlike many g scale figures. Careful painting changes everything.
more often i do use diluted true black permanent ink in 90% meths (dries more quickly) to emphasize cracks, wall and roof texture, and, often white for brick or roof tile mortar. Just enough to tone down certain features.
there is , for me, a pleasing, german toy train continuity to stock Pola buildings ( less so piko, imho). I think im enamored of the older lgb catalog photos and scenes.
but when i do paint, the change is substantial, subtle color and dead flat look being far more plausible. And, more work. Id estimate that when i repaint, it takes me 2-3 times the time of assembly alone, to prime, let dry, paint, and scrape clean gluing surfaces, etc.
Earth toned artist chalks , scraped to powder , applied with a soft brush and with spray fixative are an easy and effective compromise.