It sounds like you're taking excellent care of your little guy! The thing that surprised me the most is that you are able to handle him. Typically anoles that are handled don't end up doing well considering they're prey to a lot of animals naturally, and handling isn't seen as affectionate by them.
With that being said, anoles that turn brown or black are experiencing stress. This is most likely due to the handling, but I can't say so for sure. Your best bet is to space out any touching to every few days until your animal is comfortable with its surroundings. Even though it can be difficult not handling your pet, in an anole's case it's for the best.
As far as aquariums go, a single anole tends to do quite well in a 10 gallon tank, which are fairly cheap. A lamp for a 10 gallon tank can be 50-60 watts with the heat lamp propped on one side of the tank to create a warm and cool side for thermoregulating.
If you have any other questions feel free to message me!