Hey, I would agree with ddawg16 and a_lost_shadow about maybe putting some fencing up to enclose the patio. There's a company that makes vinyl railing that will give you a picketed look. The other nice thing about these guys is they have a product that you can wrap around your columns to give them a little spruced up look that'll also go well with the vinyl picket fence look.
You can get this stuff in a few different colors, so you could add some of the white vinyl and either paint the garage door and front door white to match. That'll get the yellow-ish color out of the way. That would make it POP!
Here's a link to one of the different kinds of railing I personally enjoyed the look of, but there's a lot of different kinds to look at.
http://discountfence.com/vinyl_fence...20railing.html
And, here's a link to the "snap wrap" that you can clip over the columns. It'll also do well to protect them I'd wager. They have trim kits too, basically molding for the base or the top as well.
http://discountfence.com/vinyl_fence...snap_wrap.html
Essentially, you have a really great start, but as far as all the options you have, this is probably one of the less expensive ideas compared to residing the whole house, or repainting the whole thing as well.
Well, good luck! Post some pictures when you decide what you're going to do!
Edit: I can't be sure, but are there no gutters? You miiight wanna give that a whirl. If you do any landscaping, you don't want all the water just pouring ontop of the plants or mulch beds. I've done a large bit of mulching myself, and when you get a heavy rain with no gutters *shudders* you'll find mulch ALL over the lawn :s You could get those to match the door and shutters probably, I think that would also look a little nice.