I am not sure , if I understand your question correctly, but for conditional formating you can go in Properties -> Visual cues in uppe or lower try to use a formula for conitional formating and if the condition in the box is true then the color in front of the textbox is applied for the text.
Visual cues will property will applicable to only PIVOT and STRAIGHT table not on Charts. But he wants to do in Combo Charts. Even i was trying to change the color but no luck.
It looks like the text color expression only works for text on the axis, and not for text on the data point. That might actually be a bug, since it would certainly seem like the position of the text shouldn't change it's color, and that the text color expression should be applied consistently. Well, it's easy to change the color if you put it on the axis, or to change the bar color by setting the background color with the same expression, but neither of those solutions may be acceptible.
