Sorry, but lights will disturb chameleon sleep. Unfortunately we can’t cover their enclosures like we would do for birds either. However, there are solutions. You could buy/build something that would block off the light. What that is depends on what materials are available to you and your creativity. I needed to block off my chameleons on the sides of a small room from seeing each other and used a free standing tension rod curtain thing.
https://www.amazon.com/gp/product/B07XTYY5HH/ref=ppx_yo_dt_b_asin_title_o09_s01?ie=UTF8&psc=1 That plus a room darkening curtain would work pretty well I’d think.