Conditional formatting for clustered column chart with Legend

I have a table that shows values for different KPIs, for a specific date:

From the month and year columns I also created another column named Date.

I have one clustered column chart that shows the monthly evolution for a specific indicator for the last 3 years and in another clustered column chart below this one I want to show the growth between years - these look something like this:

My problem is that I wanted to initially conditional format the % chart to have the columns green if the value is positive and red if the value is negative. From what I read in various threads you cannot really do that, so instead I want to at least adapt the color of the Labels based on the value displayed - red for negative values, green for positive. So I've tried to format the labels by field value, based on a measure I created named KPI Label Color: