Did you know you can just have the KPI arrows their own color in your dashboard? KPI's look less visually distracting if you just limit the colors to the arrows themselves.
I did this by making each KPI arrow their own calculation. I learned this from Will Perkins, aka Tableau expert extradonaire!
Here is an example I created in Tableau using column banding. I used the Sales calculations found in this other tip of mine.
Here are the calculated fields I created. I grabbed the KPI arrow icons using the Windows Character Map application.
Negative Month Diff
IF [MonthDiff %]<0 then '▼'
Positive Month Diff
IF [MonthDiff %]>0 then '▲'
I placed these two calculations on the Text Marks card. I opened the Text marks card to edit the Labels and placed both calculations next to each other. I also changed the color for each calculation.
One thing I didn't do in this example is to spell out if it is MoM (Month over Month) comparison. I usually add this next to the MonthDiff field in the Label.