Visit some independent garden centers to see what they have that might work. Unless you order off the web you will be having to choose from what they have anyway.

Boxwood can be kept sheared to a certain size.... if done diligently.

There’s a fair number of shrubs which could fit those dimensions without much pruning. You’ve already named some of them. Hebes , Salvias and Cistus could be added to the list. They’d need maintenance clipping to remove dead flowers and to keep them compact but they wouldn’t need pruning to reduce their height.

if you took a walk around.. you could take a few pix.. and we could ID them for you ...

Look at abelias, too. Very easy keepers.

I wouldn’t do KOs in this situation. They get large and are not fun to prune.

Ah I didn't realize that about KOs.... thanks for the tip!

Are you talking about a path to your door?

Yes, the path to our front door. It runs up along the wall to our garage door, and I'm stuck with the layout. The bed dimensions can't change, and the sidewalk up to the front door can't change either. It looks really lopsided when that bed is overplanted.

I would not use shrubs. I would use smallish perennials and grasses.

Iberis sempervirens 'Autumn Beauty', Blue Fescue, Catharanthus roseus, Dianthus, the alpine types, annual Salvia, possibly the smallest Agapanthus 'Baby Pete' are just a few plants that would work.

It comes in other colors

I'm not suggesting you use all these plants. Pick a few and group them in threes or fives.

My sister had a bed like yours. After trying many things over the years it eventually became like what I describe. She had shade closer to the door so she had Bergenia too.

SoCal has such a rich and particular menu of landscape plants that I never knew until I spent time strolling the neighborhoods of Beverly Hills and also gasping at some truly beautiful freeway plantings. I would take Ken’s suggestion to go out (to the most attractively landscaped neighborhoods near you) and take pictures of what you like. Also, when you are liberated from the lockdown, you might enjoy visiting The beautiful public gardens. All of those succulents and grasses you have to choose from!

Boxwoods trim easily to almost any shape. That is why they are used in so many formal gardens.

Box blight is affecting the use of these now, is present on the west coast.