I am trying to see what the most intuitive or most conventional color scale would be for a heat map with values that can be either positive or negative (percent difference from expected).
e.g., -50%, 0%, 50%
Scales I'm considering are:
- Blue for negative, white for zero, red for positive
- Red for negative, white for zero, green for positive
I think it makes sense for zero to be white because it's important to know that something is neutral in this case.
I like blue-red because positive doesn't necessarily mean good in this case; however, red indicating higher also might feel counter-intuitive.