I first made jam with real sugar, and noticed it got a darker color as
it was boiled. This was what I had expected, based on experience with
commercial jams. It was reassuring when the color changed, and I was
kind of expecting it too.

With low-sugar jams, I've noticed a brighter color, and I was curious
why "they" did that. When I made some strawberry jam with Splenda, I
noticed it didn't darken. Ultimately, the jam thickened somewhat, but
it didn't darken at all. The jam is runnier than the normal stuff, but
this seems in line with what I've bought commercially too.

I'm curious if my observations have been correct so far, and if maybe I
haven't looked in the right places. I'm most interested in making
sugar-free jams with the normal darker color and thick texture.