Observation: All the heroes of Time use red text, Caliborn is associated with red and Time is red on red. All the heroes of Space use green text, Calliope is associated with green, all teleportation effects are green, and there is the green sun, but Space is white on black. However, Doom is black on green, Calliope was doomed to die before the start of her session, and all confirmed heroes of Doom had telekinesis, which seems to connect space and time. White on black would make sense for Doom, because skulls are white.
Hypothesis: The death of Calliope caused Space and Doom to get a bit mixed up.
Experiment: Use John's ability to travel outside of time and space to prevent Calliope's death, and see whether this affects the natures of Space and Doom.
Conclusion: We would first need to create Sburb before we can perform this experiment.
EDIT: Also, all first guardians (Doc Scratch, Becquerel and Gcat) have Space powers, and both Doc Scratch and Becquerel have been annihilated. Their white and green color might then also indicate the link between Space and Doom.
Time ends all things explicitly, and Space protects all things implicitly, so Calliope's death hasn't really stopped her from fulfilling her role. Her death also
inspired the massive search through all of
space.
So maybe my experiment is a bad idea.