So I was made aware there seems to be an issue with color artifacts in some images recently generated with the civitai generator by this article. I looked at the images I generated myself and also found these artifacts. I have no clue why this happens, but after trying a bit around it seems like this can be fixed by setting the CFG scale to 3 in the Advanced Settings of the civitai generator. At least it worked for my two images that had artifacts. I prepared a comparison post here. Hope it works for you as well.
EDIT: Seems like this only worked for me, another user reported that it did not work. You can try it though, but no guarantee it works.