A potential risk is confusing the customers - customers have brand loyalty and recognition based off of the look and familiarity of packaging. They might always reach for the "green tic tacs" without even knowing the official flavor because they are familiar with the color, and changing the packaging could affect that.
However, a potential benefit of changing the packaging is attracting new customers who would have otherwise overlooked the product. Making the packaging new and exciting might entice new people to become buyers.
A good way to test this would be with focus groups, which are groups of people who you ask to pretend to be the customer and give you feedback on the idea. Focus groups are a good way to learn the good and bad perceptions about a change before it is put into effect.
Different communication methods are used in different circumstances because sometimes a certain method will be more effective in terms of cost, time and impact, and sometimes it will be more appropriate.
