Thanks I like the black and white

Stained treads and painted risers would look great with all of the architecture elements.

What about bright orange carpet going up the stairs

Sand, carefully, you will be surprised the difference it makes. But it is very easy to be over zealous and make them uneven. Painting is a good option, but they still need to be smooth otherwise you will make them look worse. Paint will bring out every bump, dent and crack. Use a good paint made for floors or you will be forever touching them up. Do your homework or if you are unsure hire someone. Replacing is a lot more expensive then doing it right the first time. What are you doing for flooring at the top of the stairs? Is that wood on the first floor or a laminate? If laminate definitely paint. I have also seen wallpaper done on the riser....very cute and easily changed when you get tired of it. There are even ones that look like tile.