Looks like powdery mildew, to me.

Yes, I agree. Too wet. Does that container have any drainage holes? Also your idea of keeping them inside 'so they don't get bugs' is misguided, I'm afraid. Rosemary is a full sun outdoor plant and is unsuited to growing indoors. As well as insufficient light there are no predators in the house to deal with any 'bugs' and there is no wind or rain to dislodge them. The only reason to have Rosemary indoors is if you are in a cold climate. Where are you located? Is it warm enough for Rosemary outside? If so that's where it would be happier.

Oh okay I'll water them less instead. Before I water them I feel the soil maybe an inch deep to make sure it's dry. I couldn't find a good way to check online so I've just been doing that.

I haven't seen white on it but the one behind it has it, I'm treating that one. I have noticed a lot of yellow spots on the leaves some are brown now.

Oh okay, I was reading that they can be indoors if you want a little kitchen garden so I thought they would be okay and easier to manage that way. The store I bought them from kept them indoors so I thought they would be use to it. The container its in now doesn't have any holes I wanted to make some in it soon but in the meantime I think I'll move it by itself in one of those regular black plastic containers that has a few big ones in the bottom. Before when it started to wilt it was in one of those, though it was smaller and I kept it outside. I forgot for how long it was until I moved it inside. My first Rosemary would get covered in dirt and spiders and this area has a lot roaches and stink bugs during the summer that I was concerned about. I didn't know if they would cause problems for it since it's an herb. I'm in central California. We are currently in an in between of our winter and summer where the weather is almost unpredictable but shifts from very cold to very hot. But maybe a month ago it was cold. We just had on and off rain along with strong wind and pretty cold nights. But I kept all of my Rosemary's inside at that time.

I also use a spray bottle to water should I just use a cup instead? I wasn't sure if the plants get enough water thoroughly with a spray bottle.

The store only stocks them briefly, they don't grow them there. So the conditions are not a good guide. Those articles about kitchen herb gardens are misleading and mostly unrealistic.

Water thoroughly but less often. Use a small watering can or jug. And any container for any plant must have drainage holes. (Except a waterlily!)

I'm guessing nowhere in central California would be too cold for Rosemary outdoors at any time of year. It grows fine over here all year round. But if it's been inside it will need hardening off.

Oh okay, I definitely want them to live so I won't keep them there, I put them outside this morning. Thank you so much! Can I ask one more thing, is there a potting mix that you recommend for them? I did some research on the one I had just bought, it's suppose to help with drainage but it also retains water. The one I had before for my first rosemary someone gave me but I believe it was for cactus' and palm.

The cactus one would be better. I have to confess that since my Rosemary lives out in the ground potting mixes are not my thing. Can you just plant it in the ground?

Oh okay, unfortunately no, I live upstairs and I only have a small porch.

full sun in the desert. It needs sun and good drainage to be happy