So, the Realm (no, not the Forgotten Realms) from the D&D cartoon had some unique geography and astrology. I'm not sure if it'd be possible to exactly recreate the cartoon, but there were some unique features that I think could make for a unique setting based on it.
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Thoughts?
On the four suns, colours, brightness, and apparent relative positions:
I’m a theatre technician specializing in lighting design, so this hits close to home. Physics and optics won’t explain everything but it can solve some of it:
1) Suns merging to white when combining. Mixing light of different colours mix toward white (white being the sum of all wave lengths of the visible spectrum combined). Multiple suns emitting different colours mixing to white light makes sense physically speaking.
2) Two suns instead of Four. A conjunction of all four suns eclipsing is probably rare, but perhaps two pairs of suns also eclipse simultaneously but separately. Since they both merge to white suns, I'd say Yellow and Blue as the large sun/eclipse, and Magenta and Green as the smaller sun/eclipse.
3) Relative distance. This can be explained in two ways. A) The Magenta sun is farther than the two smaller one but brighter. An optical illusion, caused by refraction of light, makes it look like the Magenta sun is in front, but it's actually behind. B) Sometimes the smaller suns are in front and sometimes they're behind, because these suns rotate around each other. I'd be interesting to come up with some sort of solar system model for it. If i had to guess, the three smaller suns form a tripe system orbiting a larger sun.
4) Darkening during eclipses. To a certain extent, it makes sense that the planet altogether receives less light if the suns all eclipses one another. If I install four theatrical lights in a row, they'll each cast shadows form the previous one along a specific axis. Would it be enough to go night-dark? Probably not, but hey, it's fantasy.
5) Other possibilities. Some phenomenon prevents the light from those suns form reaching the planet. Some field of space dust and asteroids in an orbit that eclipses the Realms' planet? Does it simply happens to align with conjunctions of stars? Some form of magical phenomenon, intentional or naturally-occurring, runs alongside physical/optical phenomenons? All four suns, or perhaps just the three smaller ones, are the same colour, but whatever wave-length reaches the planet depends on its current distance/astronomical position?
Regardless, there are many possibilities even before involving magic, and all are fascinating if you ask me.