I'd do a tight ground cover like pot-o-gold or creeping thyme. Even English ivy.

We did have quite a bit of ground cover, but it grew like weeds and started suffocating our bushes, so we removed it. Is Pot o gold or creeping thyme a slower moving ground cover?

we're in Utah

check to see if any of those plants I listed are still perennial in your zone. I'm not sure what zone Utah is. Here in Zone 5, hostas grow well, and you can split them after a couple of years (very easy, just catch them when they're sprouting and literally drive a shovel right down the middle and take some to another part of your yard and throw them in a dug hole). They're really easy to maintain, and might look nice in that space. I'd google Rock Garden and see if you like those types of gardens. I think it would be more fitting than shrubs. Especially in low light.

That's a lot of boulders in the front of the house. I'd strategically place them throughout the property(put some in the backyard). You might even consider breaking some of them up, and placing them where they are now, but smaller.

what is that planted on the other side of your driveway by your car in picture2? You'd want to mimic that if you can on the other side (by the boulders), but if it's a full tree, you'll just have to try to find a small shrub or plant with similar foliage (color)

Allison, those are trees along the front of the house. We have the red tree by the other boulder next to the lamp post.

Try to bring some of that light green into your rock gardens. Creeping Jenny might look cool between the rocks. I'd stay away from adding more shrubs there, as the boulders are heavy enough. I like the pots on the walkway, evens things out.