Color binding for trackmap

Hi,

I'm trying to color-code the sectors on the track map to show different colors depending on the best sector delta.

I've added the following to AlternateTrackSectorColor and TrackColor, but it doesn't seem to work. Either the whole track goes orchid or tomato. Is there a way to make it work or can't I use functions for the trackmap?

var sector = timespantoseconds($prop('IRacingExtraProperties.PreviousSector_0' + (repeatindex() - 1) + '_DeltaToBest'))

if (sector < 0) {
	return 'Orchid'
}

else {
	return 'Tomato'
}