I’m not sure if I’m completely clear on the question so correct me if I’m not.
Your asking what color to paint the cinderblock walls?
I would leave them. Honestly. They’re not horrible. And I know you said plants are tough. But what about even a faux boxwood sheet nailed in there. Or some evergreen trees lining the front. Or even vines.

I should have added your house is awesome. Looks so fresh and cute. Backyard is a beauty. Looks like you found a gem!

I think if you paint you’re setting yourself up for maintenance. Embrace them - you’re in Arizona & they‘re everywhere! Once you add things to look at, you’ll stop seeing the wall. Looks like rock on ground all around fence so maybe inground planting not an easy option. You could invest in huge & decorative pots, place strategically & fill them with permanent type colorful plantings. It‘d be good if you’re able to install some kind of drip system to provide summer water - even one you hook up to a hose that waters all at once & on timer for low maintenance. Maybe also keep your eye out for wall art to hang which would add another dimension of color & design.

Paint the walls. There are painted cinder block houses all over the place. How often do people paint those houses?

You should know the name of the finished house color. Find that color on the store paint chip. Choose another color from that chip. That color could very well be the lighter green on the mismatched back side you painted over. That lighter green would be a good color for the walls with the darker house.

Thanks Christopher! Exactly the feedback I was looking for! :)

I'm not in AZ but totally love the xeriscape look. Nice house!

Repose Gray by Sherwin Williams?

I would paint the walls & agree with Christopher regarding color. No gray if you’re trying to steer away from the prison look.