An addition of one more colour makes it harder to meet the orders.
Moon struck will prevent candies matching the colour on the left side of the moon scale from spawning. If blue, green or orange colour appears on that side, 58 additional candies have to be collected in addition to the 8 candies they have to collect eight moves after the moon struck. This has to be repeated if any of those colours appears again on that side.
The orders are worth 75,000 points. Hence, an additional 15,000 points is required to earn one star.