White is going to show dirt (outside) and hair, if you have pets..(inside); there really is no way around this. I would use Kilz as a primer, it's an affordable, good product that has always given me good, dependable results. http://www.kilz.com/pages/default.aspx?NavID=61 To prime new wood: KILZ Original, KILZ Odorless, KILZ 2 Latex, KILZ Premium, or KILZ Exterior primers KILZ Original primer, KILZ Odorless primer, KILZ 2 Latex primer or KILZ Premium primer can be used as a primer/sealer on new wood and millwork without raising the wood grain. On exterior jobs, use KILZ 2 Latex primer, KILZ Premium primer, or KILZ Exterior primer. As an enamel undercoater: KILZ Original, KILZ Odorless, KILZ 2 Latex or KILZ Premium primers KILZ Original primer, KILZ Odorless primer, KILZ 2 Latex primer and KILZ Premium primer are excellent enamel undercoaters, though many painters prefer KILZ Original primer or KILZ Odorless primer due to the product flow and fast cure time for sanding. I also like Behr Paint. It too is affordable and has proven to last well, and clean with little, if any problems. What ever brand of paint you choose pick one that is formulated for PORCH, DECK, WOOD! I believe it comes in Semi gloss or High gloss. I'd sand well, clean the surface perfectly, use two coats of the primer and probably two coats of the paint as well. You can add a sealer to that if you wish. It MIGHT help with both protecting your paint and provide a smooth surface for easing your clean up. However...if this is a high traffic area...they still maybe some chipping...you just plan to touch up seasonally as needed. I have some painted wood floors and the front and back porch entries. The Front hardly ever used has NO chipping. The back HAS. The more used floor in our bedroom has also chipped due to the dogs..I did not seal it, and some minor furniture moving.

Why would you paint over wood?! Won't that lower your home's value?

You'd be a dullard to do so. It's better to go for wood stain instead if you have natural wood stairs. Else if it's laminate then a buffer.

Can't find a worse color?