Graphic builder 6i

[nadia]

Hello
I have oracle developer 6i and oracle database 10g.
In the report I want to display the chart's bars or the lines in different colors depending on the values.
For example employee in sales department whose salary over 1000 $ and have commission will display in red color while the employees who has the same properties but his salary is equal to 1000 $ will display in green color, and the employees who has the same properties but his salary is below 1000 $ will display in blue color.
how can i make graphic builder do that?
regards