Hello Doug,
I have checked the child where positive color is not blue. It seems like the color has been set manually in the configuration of visualisation. This overrides the palette colors that have been configured per workspace.
When I created a new visualisation from scratch with the values you have used, it creates positive as blue, negative as red and neutral as yellow.
Also one important point is that Order of precedence matters: user setting > workspace setting > organization Appearance
Please let me know if you have further questions. Thank you