Conditional formatting in a clustered column chart

Et1w

Sorry for misleading you, I did not understood the question at first.

You can do that, and here is how to do it step by step : 

1 - Add the value you want to use as a color filter in the Color Saturation field 

2 - Go to the Data Colors section in the Format area, it looks like that : 

3 - Input the value as it follow : 

Here I've put 999 999 as minima so that everything below is black and not half yellow half black

- Quentin