maybe this color? http://www.benjaminmoore.com/en-us/paint-color/breathoffreshair

Not sure we have total understanding of your needs... what's wrong with current neutral color?

I definitely like the idea to paint the railings white. Great idea

I agree - I would keep the current color but paint the railing white to match the doors and the trim

You can use a tinted polyshades to tackle the newelpost and bannister, but let them paint out the spindles. As for paint color, though blue could be lovely, with the dark wood you would want a very muted color - the blue you show us is too clear, so will give a nursery effect. Also, then everything would need to relate to blue and brown through the entire home - I think you may just want a better / more updated neutral than the builders beige. Try ben moores cedar key . . and pick out one accent room - dining? to paint in a muted blue green so you get a shot of blue to start with - whythe blue is a good one, and test also templeton gray - here are some links
http://www.benjaminmoore.com/en-us/paint-color/cedarkey
http://www.benjaminmoore.com/en-us/paint-color/templetongray#ce_s=templ

You seem to have a gray/green color in the back area (dining room?). You can play off that or carry it to the other side of the house, like the wall the staircase is against.