I've got an herb garden/planter just out my front door that I love, but it's missing a thing or two. Needs some color without a doubt.

This is the planter as it is today - http://www.gthomson.us/projects/food/herbgarden1/lateaug2017.jpg

It's on the North side of the house in Southern California, so it gets very little, if any, direct sun.

I just had a new roof put on that is a lightish grey, and I'm liking the way the primered fascia boards look in white, so will be having them actually painted white - http://www.gthomson.us/projects/roof/new/curbview1.jpg

And the house colors will be the slightly darker grey in the first link above, with the trim being refreshed, probably a very similar blue.

Would love to add some red and yellow ornamentals in that planter, but I think that would just really look awkward in the whole color scheme of things.

The plant on the left I'm hoping will grow a lot to fill in much of that space in the corner.

I feel like adding in blue/purple ornamentals between the existing plants will blend too much with the house. And while I think some white ornamentals could be good, I was also looking for some color.

So far, my best thought is some red/white Plumeria for some height along the side of the house and for some color, and some small white flowering plants added in between here and there for interest.

But my color and design sense has never been one of my better aspects.

So I'm looking for ideas, opinions, plant types and colors that may also fit in well.