Conditional Formatting of Bar Chart

Hi Team,

I need my data bar to have only two colours. I have an average line. The value below average should have red and above should have green. When I apply the field in colour saturation and in 'Format' when I give color code for Minimum ans Maximum, I get bars in the middle with combination of both green and red, values above one are a gradient shade of green, and bars below one are shades of red. I don have any fixed value to be given as minimum and maximum as values changes dynamically with average line. 

Can you suggest a way to sort this. 

Thanks in advance.