You can create a second field to color by:
IF [1-DIV] >= 0 THEN 'Positive'
ELSEIF [1-DIV] < 0 THEN 'Negative'
Add this to the [1-Div] Marks Card as Detail. (If you add it as a Color, it will overwrite Measure Names, which we don't want to do).
Then Click the 1-Div Color Pill's Detail icon and choose "Color"
Now you have two Pills to color by: Measure Names and 1-Div Color:
Now choose your colors. You'll have to set the Negative color, then move the parameter until you get a positive number in order to set the positive colors.
Workbook is attached, hope this helps.
SAMPLE (5)_v2018.1.twbx 13.6 KB
Same thing Jennifer did.
PS: Very good explanation, Jennifer -- especially the part about forcing a negative value to set the negative color.