No photos and zone 6 encompasses a very wide area with very different growing conditions. A location is better info.

Tropicals in zone 6?? Maybe cannas. But most tropical will need to be dug in fall and stored over winter. And not exactly in character with a "traditional colonial style"

Lack of any evergreen plant material leaves a very bare looking space for a good 6 months of the year. You OK with that?

Sorry, my photos didn't load the first time. Here they are.

I am in South Central PA. I have been using cannas next to the house on the right side, and my hubby digs them up very year. I think we can do this for a few more years, but eventually we'll need to transition to something permanent there.

There are hollies on the left side that were doing well until last year. We are treating for fungus now and hope they will bounce back. I like hollies and I am open to other evergreens (especially if they bloom), but they must be something that won't desiccate too easily given the intense sun and winds. Except for boxwoods. I have a totally irrational hatred of boxwoods.

Well, for the front of a home I'm only going to recommend conifers or broadleaved evergreens as your major players for year round tolerability. Then I'd use perennials to punch up color during the growing season and large pots of annuals for color on either side of the entry that you can move around or switch out as needed.

I'd use nothing but conifers to the left of your entry on the house side of the walkway.

I'd use low perennials in front of the walkway- long bloomers like catmints, salvias, little veronicas- small lovelies.

I'd wrap a bed around the tree on the right, curve it in then back out again as it ties into the driveway. The bench goes inside the bed under the tree with the shade plants.

"I am not a fan of traditional green shrubbery foundation plantings and would prefer something with tropicals, flowering shrubs, and perennials."

Everybody thinks this is what they want, but do you really want bare branches greeting your houseguests on Thanksgiving and Christmas?

"Traditional green shrubbery foundation plantings" serve a purpose- to screen the view of the foundation and to nest the home into the site.

Do you only want to do that May through October?

Think it through.

"Foundation" plantings also serve as a foundation to build on- a backdrop that serves to better feature the bloomers and stunners that only show their colors a few weeks at a time.

The tree on the right is quite close to the house. Could you bring in an arborist to prune it?

Maybe an abelia would work -- you're probably in the northern part of their range so they might die back some years ... but that could be a good thing because it would keep them from getting too large. Small leaves, but lots of butterflies at abundant flowers all summer long. Very tough plants could stand afternoon sun and regular winds better than many. Here's a link: abelia tough but beautiful

Bright flowers -- daffodils, rudbeckia, daylily, lily, coreopsis, annuals such as zinnias and marigolds -- could be tucked in anywhere.

You didn't ask but your front door would look great with a more robust, traditional surround, such as the 'triangular pediment' below:

About the hollies on the left side - if they don't fill in, what evergreens would you suggest to replace them? The bed is only four feet wide, and I hate shrubs too close to the house or above the windowsills. 

Should I put a matching row of evergreens along the right side too? It's much shadier there and I'm afraid the sunny side bushes would always be larger, so the symmetry would be off.

Any suggestions for shutter and front door colors? The front door used to be reddish burgundy with a white storm door, which looked nice, but the door got hot enough to burn skin in the summer sun. The light color fixed that but it's so boring.

Thank you all for the excellent ideas. There is actually a bed that wraps around the tree already, but it is very hard to see in the photo. The bench won't fit in the bed itself and it would be difficult to extend the bed due to a drainage issue, but the bench would definitely look better under the tree at least.

We did have a pediment that came off when we replaced the front door. We need to install a new one.

I love abelias and didn't realize they were so tough. Maybe a mix of evergreens and abelias would give me the best of both worlds? 

The perennial suggestions are great too and will be perfect in front of the brick walk.

I'd plant a pretty tree like a crabapple on the left side as of your home...so as you're walking up the sidewalk it's on your right side, not the side next to the foundation. I think it would give some balance. Then you could use some base evergreens and add in colorful shrubs...maybe something with a beautiful scent like a miss kim lilac or a scented viburnum or even a rose. The knockout rose Sunny is a yellow rose that has a wonderful citrus scent and is easy to grow. Have fun..

and most importantly, plant what you love and create a pretty view from Inside.