In the iOS camera you can point at something white, like white paper lit with white light, and long-press to get an auto focus and auto exposure lock. Then you

In the iOS camera you can point at something white, like white paper lit with white light, and long-press to get an auto focus and auto exposure lock. Then you can take a picture of the orange sky / landscape and it will use the locked white balance setting. A white countertop lit with fluorescent light would work.