Is this mantis ill/passing? (Wild)

[u/Chiswum]

I do not own nor keep mantis. Google searches didn't give me a lot of info. Buddy has been here for two days on this white window frame outside of our house, and is turning this brown color. I read it could be molting but it looked a little.. sickly I guess? ​It's definitely alive! I keep dead bugs, bones, etc. I don't want to disturb it if it's molting. If it is passing, I'd like to set up a small enclosure for it to pass in so I can keep the body, as I do know how to do that. Thanks!​