Boas can actually go through some pretty drastic color changes depending on how they're "feeling." Hogg Islands tend to be the most drastic of all of them, but Columbian normals can also change quite a bit. And because of the brightness of the hypo morph, you can notice it more... when I had them, I noticed that they could swing from really bright to really dark (and it wasn't a shed change). They also seemed to be more curious and open on lighter days, and, well, sleepier on darker days lol