PokerTracker

Example : I set colour ranges for flop cbet : 0-40 to be green , 40-60 to be yellow , and 60-100 to be red.

See attached, after clicking "apply" and "ok"

and it Still doesn't work ! Please advise !

For PokerStars and the replay of PokerStars hands you are limited to two colors in the Color Ranges area as that gives 3 colors (including the default foreground color). If you set your foreground color for that stat to red though it should work as you want because your other two ranges take up all other values.