You haven't gotten an answer probably because you have provided no photo. Lots of people won't bother trying because they have no info to work with.

Let me ask you this. What colors are in the upstairs rooms that open onto this hallway? I do not believe room colors have to match. For me, if there is a doorway it's an opportunity for a color change. However, you might find inspiration with a similar or contrasting color to one that you already have. White paint is never completely white. Most whites are tints of yellow and browns and tend towards beige, but you can find pale blue and green whites as often as not.

There is no reason your curved wall can't be interesting. Add wall stencils to make it a focal point.

Revere pewter