We're in Northern California zone 9b and looking for cost concious-widely available (Home Depot) plants for a small section of sloped area - semi-sandy soil.

I've kind of put in a few hodgepodge things for now - the one in the 1st pic is something OK that's doing well (don't know the name - plant ID?) that seems to be a decent colorful ground cover. I could do more of this if I can find them... Other ideas would be great. Maybe something where I can plant just a few and they would spread? Or maybe layers - sections of different plants.

This is a view from above of the slope - it's maybe something like a 30º grade - there is one little 1/4 pie slice like this on two sides of a hardscape stair.