A Portal is a space-time continuum hole which connects two or more separate universes. The place that has the most Portals is the Universal Central. All Portals have different coloration depending on where they lead to. Portals that lead to the Universal Central are purple, pink and navy blue. Entering a Portal may cause the appearance of a character change to match that of the natives of that universe. They are very important to the plot of the FDUS.
Portals are used by Destonator to send in Shalos or other creatures like King Cropolite to attack the Heroes. But they are used by the Heroes to follow creatures like The Ship-Shifter, knock out enemies like Ridley, or make the Hero Group bigger. After something has crossed the Portal, it is only a matter of time until the Portal vanishes for long periods of time.
Portals never existed before Destonator carved the Universal Central, which destabilized the space-time continuum and makes a hole in which two universes connect. The Universal central is the center of all that, hence it's name, so it has the most Portals. They take a spiral shape and, the bigger they are, the more they act as a magnet and suck in things. As the continuum destabilizes more, more Portals appear across the universes. But the Portals appear in random spots, so many universes are not aware of their appearance because they appear across the universe (not inhabited).
Their coloration depends on where they lead to. Ones that lead to the Universal Central are purple, pink, and navy blue, as mentioned above. Example: One that leads to the skies of Pop Star are going to be yellow, pink and red because the Portal seeks the main hero's coloration and the dominant color of the planet, as crazy as that may sound it is how it is.