Are the posts and spindles really at an angle? I would definitely replace them then. I would go all wood stained medium to dark.

Your front door is black, I would paint it all black it would look good with carpet as well and Keep the modern/traditional look

I like black and white. White spindles and black banister. You can also have black on bottom (wood that spindles go into).

I totally agree with KK. Paint the rails black and leave the spindles white to start. If that isn’t dramatic enough for you, paint it all black. The only problem I can see is the rails. They look dated.

One more thing- see about changing the finials on the posts to something more substantial. Finding a good fit might be hard, but I’d definitely look. The end caps in Beverly’s picture are gorgeous.