YO I HAVE JUST FOUND A COLOUR FILTER IN MY PHINE THAT MAKES EVERYTHING YELLOW, HELPING ME READ LARGER CHUNCKS OF TEXTS AAAAA. HOLY FUCK I CAN ACTUALLY READ IM GOING TO CRY.
Any thoughts you'd like to share on why Spirealm was so yellow?
Hello, and thank you for your question, anon!
I have Many Thoughts, so apologies for the rambling essay that is going to be this answer.
There are two reasons why I think the production forced the yellow filter on everything, and one has to do with general film-making practices, and the other has to do with the plot, which might have spoilers, so everything will be under the cut!
Before I get into the plot reasons, let me briefly talk about how lighting is used in visual media, especially in art. To put it very simply, there are two kinds of broad lighting choices: North lighting, and indoor lighting.
North lighting mimics daylight in the northern hemisphere which hits the subject and creates cool, soft shadows and is commonly used to depict daytime scenes.
This is what North lighting typically looks like when applied to paintings:
Notice how the shadows are very blue? That is because shadows are generally very desaturated, and they tend to pick up color from the environment, and in this case, there's a giant blue screen on top, which is the sky.
There are other more specific examples of North lighting, but I'm going to ignore them for now.
To come to the second kind, it is indoor lighting, where the light source is typically warm (again, there are exceptions, but I'm not getting into them now) and is less bright than sunlight. The shadows cast by an object in this light are generally warm, like in this painting:
Obviously, some scans of this painting tend to show up more green than others, but this is enough to demonstrate my point for now.
So what The Spirealm does is use more indoor shots than outdoor daytime ones, which means more warm colours than cool ones, like these scenes:
So these scenes would normally have warmer shadows already, but what the series does is add a yellow/orange filter on top of it, which increases the saturation of the warm colours already present, and makes everything look fuzzy and glowy.
In contrast, here are some scenes shot in natural daylight:
We can already see the blue/green shadows in these scenes!
Coming to why the yellow filter was used as an artistic, storytelling choice (not one that I agree with, mind you) is because the yellow filter is typically used to depict tropical countries, deserts, older civilizations, or just because the film-makers couldn't be bothered to come up with a different visual cue to depict cultural differences in films. So when the yellow filter is just slapped onto most of the scenes in the series, they tend to be part of the door worlds, and typically night scenes in them. So, in a way, the series is telling you that visually, the only way to pick out a door world from the real one is to go with the color grading in the scenes.
But when the yellow is also applied to scenes in the real world, such as this one right here:
What does that mean with regard to the plot?
Now, I assume that you are already familiar with the novel and series endings, if not, skip to the end of the post: one of the major plot points is the inability to distinguish between the door worlds and the real one. So the production team used the yellow filter as a visual cue for door worlds, and by using it on other scenes from the real world, it is trying to hammer home the point that technically ALL of it is happening inside a door world.
Does that make any sense? Or maybe the production team didn't think this far.
Anyhow, these are my two cents on the subject. But personally, I abhor what the yellow filter does to the scenes, because it pretty much renders everything monochrome at this point.