I have a very basic chart, one dimension (date) and one metric , Contribution = SUM(a) - SUM(b) , which can take both positive and negative values.
I would like to have a conditional coloring of the bars so that if the value of Contriution on a given date (bar) is positive, we have it green, else red.
This works if I set the conditional colouring in the Expression tab. However I would also like to use two-colour bars, which to my knowledge I can only achieve in the colour tab. But here, the formula IF(SUM(a)-SUM)(b) > 0, RGB(0,255,0), RGB(255,0,0)) seems to be evaluated over the whole set, and not per each dimension point (date). Is there any way to achieve it?
Just went through my OP and realised that the most important bit of information is also the least clear one. Sorry, my bad.
I would like to have the bars in two-colour gradients, so that positive values are shaded in, say, RGB(0,255,0) and RGB(0, 150, 0) and negatives in RGB(255,0,0) and RGB(150,0,0).
As far as I know it is not possible to create gradients in Expressions/Background Color so the question is whether it is possible to have a conditional that is "sensitive" to the dimension points in the Colors tab.