A sweet and colorful childhood favorite cereal is making a major comeback. Lucky Charms, the "magically delicious" cereal featuring oats and marshmallow bits, has been flying off supermarket shelves despite a trend toward healthier breakfast cereals.How much has Lucky Charms' luck improved? The leprechaun-represented cereal's sales rose 20 percent in the last year, according to the New York Post.This classic cereal hasn't been resting on its multi-colored laurels. In February, General Mills introduced a new trend-inspired unicorn marshmallow, with a white body and colorful mane; it was the brand's first new shape in 10 years, replacing the horseshoe. They also offered cereal lovers a whole new way to enjoy those marshmallows in the form of Lucky Charms Frosted Flakes. While competitor Kellogg's manufacture the cereal known as Frosted Flakes, the term isn't trademarked because it's a generic term describing any cereal of that type.What explains the eagerness to enjoy this sugary cereal for breakfast? According to Dan Goubert, founder of the breakfast blog Cerealously, Lucky Charms has a major nostalgia factor driving its rise in sales. Plus, while kids love that it's colorful and tastes good, for adults, there's a deeper resonance. "Lucky Charms makes them feel how they did as a kid again, at least for a little while," Goubert told The Daily Meal. "I also see Lucky Charms as one of the last bastions of shameless artificial coloring in a cereal aisle where everything is becoming more natural. So for adults who think a little guilty pleasure is still valid, Lucky Charms stands as an old guard of a waning era."In addition to nostalgia, Goubert said sugary cereals are being enjoyed as a late-night snack, a complement to a healthier diet, rather than as a sole source of energy at breakfast time.The unicorn factor won't have a "lasting impact" on Lucky Charms' success, according to Goubert. He believes the unicorn is slightly out of place among the single-colored hearts, stars, and clovers.Another reason the cereal might remain so high on our list of breakfast foods? The marshmallow shapes are actually made of marshmallow ingredients. While of course a typical marshmallow wouldn't hold up to milk, those found in Lucky Charms are formulated to fit right into your cereal bowl.Cereal expert Goubert also noted that the mashup of Lucky Charms and the sweetness of frosted flakes was a novelty. "Where other brands like Cinnamon Toast Crunch, Frosted Flakes, or Pebbles have been trying outlandish spin-offs with mixed success, Lucky Charms largely sticks to what works, usually only changing the marshmallows so customers still know it's a reliably tasty flavor," he said. "That's why, when they finally break the mold with something like Lucky Charms Frosted Flakes, decades of expectation are subverted, and people just have to know if it's worth it."In the era of social media beefs between brands, such as the Twitter flame war between Wendy's and Burger King, Lucky Charms isn't just talking, but actually developing new breakfast offerings. Though they're hopping on today's biggest food trends, the classic marshmallow shapes will probably outlast any novel offerings. At least unicorns aren't nearly as bizarre as other food trends throughout the years.