Change Chart color.

Good evening, I have made a chart that updates itself on 3 values from a table, one of them is the amount it has to be reached by the end of the day, another is the amount it should be covered depending on the hour and minute of the day…and the last and most important is the amount worked and finished of the day…So having that explained, I need ther last char to change color depending on the amount it should have been covered, if its below the estimated to be RED and if its above GREEN…any help would be appreciated.