With a veiled chameleon, you can safely aim for about 30-50% humidity during the day. Since you are doing the naturalistic hydration schedule, you will want to reduce the nighttime humidity levels. At night, aim for about 80% humidity. This should reduce the daytime humidity levels with less water in the air while giving your cham enough humidity/water to stay healthy and hydrated at night and dry out during the day.
Often times when people reach 100% humidity, they are putting more water into the air than precisely 100% humidity. The hygrometer can only tell you when you have reached 100% humidity, not when to stop misting/fogging. I would only recommend people aim for 90-100% humidity if they have a dehumidifier or live in a very low humidity environment that dries out the cage during the day down to 30-50%.
In sum, aim for about 80% at night. This should allow for sufficient hydration while allowing your cham to dry out and have a nice and healthy shed during the day. Less humidity put into the air at night means that there will be less humidity in the air during the day.