Card Background Colour for Positive/Negative

Hello All,

I have 2 measures that I have used to show 'Current Units Occupied' and 'Same Period Last Year'. After this I have a 3rd measure to show the % increase/decrease. This is displayed on a card.

However I would like the colour of the background to dynamically change so it will show red for negative and green for positive. But this doesn't seem to be possible anymore? Solutions I have found appear to be outdated. Is there any workaround this? As currently the background formatting is locked for numbers, not percentages or negatives.

Any help much appreciated.