[Pontiac]

Being to advise or reprehend anyone, consider whether it ought to be in public, or in private, presently, or at some other time, in what terms to do it, and in reproving, show no sign of cholar, but do it with all sweetness and mildness.

I think the modern word here would be color. As in a face flush with anger.

[Albion Wilde]

Choler means visible anger.

[Bigg Red]

I am thinking that the “cholar” here is more along the lines of the obsolete word “choler”, which, I think would have been in use during this time. This word referred to bile, but also was used as a show of anger, in the same way we might say, “Don’t get your dander up!” they might say, “Don’t let your choler show!”

But this means the same as you interpreted, and I am betting there are FReepers reading my comments who are thinking, “Who cares?!” But they are not word nerds like me and like you probably are.