Brown Paint round brown plastic windows?

The mother-in-law's house had CR Smith plastic windows installed about 23
years ago (before her time).  The various oddments of wood that remain were
painted a matching brown which now, after all that time, needs to be redone.
What would it be?  Dulux doesn't seem to have a shade called sh*t in its
range.

People talk of Sadolin - is that a paint or a stain? I do think I need a
paint - unless the old stuff was a polyurethane with a brown admixture?

I'd dearly love to paint everything white, including the brown plastic - but
presumably that is an awkward task too?

Geoff