Having trouble setting a task color in Omniplan

I am trying to set task colors in omniplan. Can’t quite get the syntax right. I’ve tried all kinds of variations of chaining the task-to-color elements with no success. Any ideas?

tell application “OmniPlan”
repeat with t in tasks of front document
set value of color of attribute of color of t to {0,0,65535}
end repeat
end tell

tell application "OmniPlan"
	repeat with t in tasks of front document
		set value of attribute named "gantt-fill-color" of style of t to {0, 0, 65535}
	end repeat
end tell