Below is a picture of my Peugeot Bordeaux. It's mostly original except the pedals (which I still have) and the leather saddle (which a relative lost). I'd like to replace the saddle and get some new tires.

I don't know if you can see them well or not, but there's a blue bottle cage on the bike and a blue bag under the saddle. I didn't pick blue for these items for any particular reason and in fact, the bottle cage was just given to me, - but I like the color.

I saw a used saddle at my LBS that was blue down the middle and black on the sides. I was also thinking of getting blue tires with black sidewalls. Bad choice? Would I be better off with just a plain black saddle and yellow or orange tires?

There are black aero bars on the bike now, which may get replaced with white ones. Either way, they'll probably not be on all the time.