[Lizard]

You would still need to set up the style manually in your OmniPlan document. In the Project: Styles inspector, click the + button in the lower left to add a named style and then customize it to match your styling. Maybe you want black for when the budget is positive and red for when it's negative? So make a style each for 'Positive Budget' and 'Negative Budget'.

Then in your script, you would add and remove styles from the budget items as in the code I included above.