You can't go wrong with salvias for the location you describe. There are many different varieties that will work.
Check out Las Pilitas nursery online or Flowers by the Sea, both are in California & are excellent resources for salvias of all description.
Hope that helps.

Thank you. I am looking at Las Pilitas nursery now, and have looked at Flowers by the Sea (I plan to order a Salvia regla from the latter in Spring).

Below this wall (actually, in front of it) is a row of other plants including Salvia, Verbena lilacae, a couple of roses, and Penstemon. I think I'd like a row of a single color above to border the mix of plants below, but I'm not sure.

Salvia leucantha kinda goes dormant in the winter and is best if cut to ground each spring. I'm a bit colder in winter than you and mine were sticks by Feb.
I took them all out and replaced with ceanothus and dwarf bottlebrush 'little john'.
Something else you might look into is bush germander teucrium fruticana. It is blooming now and the blue purple is very remarkable. I like the gray foliage something different other than green. I thin it every other year. Hummers and bees love it.
I also use a lot of sweet pea bush and other salvis.

I have too many favorites, but most of them get relatively large. In your area, I'd likely use Coyote Bush 'Pozo Surf', which can reach that height. All the salvias aforementioned are wonderful and provide such intense chaparral fragrance. Manzanitas (like Ian Bush) would also work pretty well in that location too. Or perhaps Adenostoma fascicularis 'Black Diamond'. There's too many to choose from! >________

I am on a similar search and was looking at Indian Hawthorn. Love the looks of that bush germander and sweet pea too! Anyone know if the germander would be ok in zone 10? Monrovia says only to zone 9...?

cetacea33, on the zones pay more attention to the Sunset zones than the usda zones. If you really are here in Socal you should be fine. I get high temps to 113 and lows to 28 and its fine.

Dwarf Oleander?