On the OP - copper first, bronzed second.
That's bronzed, but depending on the lighting angle as a result of the surface not being planar, it is possible to get considerable apparent variation in colour which is not always obvious in hand.
Bronzed copper is correct. The flan is copper with a chemically produced bronzed finish.
In hand it is usually fairly easy to say which is which, with the caveat that there will always be one of two which are a little ambiguous. The main thing is to ensure you are comparing apples with apples and not pears, because depending on the period in which a coin was struck, the bronzing can vary in colour. Toned copper examples however are reasonably consistently dark in colour with any multi-hued colours depending on the lighting angle. I've put a few things together to show some differences, but given there is variation even within a period, don't take these as definitive examples.
The main point is that bronzing is done to produce an even surface colour which doesn't exhibit the greater variation in toning seen with copper. Medals are frequently bronzed for this reason. Obviously, when you have full red surfaces, the coin is clearly copper and not open to question.
This will take a few posts, so bear with me. Sorry they are all unfashionable halfpennies and not pennies, but the same principles apply.
First up is an Early Soho bronzed (P935) left, compared with a Late Soho copper (P973) right. As you can see, the bronzed finish has an even colour across the surface.