How do I create a conditional 'Colour Measure' for the 'value' column?

Thank you. The first code you wrote is closer to what I want to do however if I use it it would always make the bar green as the total is always greater than zero. What I was o=planning to do is to make a bar chart for each category A,B,C,D & E where the colour measure would work for each one. So Total A, Total B etc. I understand that it could be done by creating an individual colour colur measure for each one but it would be lengthy and I was wondering whether I could just make one colour measure that would take all scenarios into consideration.