I am wrting a supposedly dark novel but it still keeps to be somehow bright. Is there any way to convey the darkness of horror in a book? I had a similar experience with the book Necropolis but this, I think should be slightly different. This needsa to be the Investigation/Lonely type of darkness. Please, if you have absolutely no experience with this then do not tell me to use black fonts. Thank you.
Read H.P. Lovecraft's The Outsider. It might give you some good ideas. And House of Leaves - it has a very interesting way of showing darkness in that book, but thankfully with the Lovecraft story, and unlike House of Leaves, you do not have to pay to read Lovecraft.
There's multiple ways to convey horror/darkness. How you describe setting will help get the horror tone you are looking for. Keeping the weather gloomy, having characters describe things in negative ways, all of that can help. When using similes and metaphors, go for ones that contribute to mood, like "the mud bubbled up between his toes like pus" (okay, lame example, but hopefully gets the point across). Keep the pressure on your characters. Don't let them win, ever (until they absolutely have to, of course, if the ending is a "win" sort of ending). Also, isolate your protagonist, take away help from him/her supports. Hope those ideas help
I never research anything so don't quote me but I believe "This Blinding Absence of Light" was written by, or in the character of, a French soldier imprisoned during war. I loved that book, especially the part about the guy that hung himself by tying his sheets to a bedpost and stretching his legs out, since you couldn't do it from the ceiling. What an innovator!
I literally had the exact same problem with my novel that I just (sort of) finished. I wanted it to feel dark and foreboding but it just didn't seem to come across that way. Ultimately I feel like the best thing I did to get it closer to what I wanted was just using the right diction, and trying to get the "darkness" across through the general atmosphere of the writing, without being too obvious or in-your-face about it. The exact words you use to describe have a big effect. For example, say you're going to describe something, even like the sun, instead of saying how warm and bright it is, focus on all the negative aspects. Talk about how smoldering and blinding it is, how its rays burn the skin, etc. It's not a great example but hopefully you get the idea. In addition, choosing the right setting can have a major influence on the overall darkness of the story. And it doesn't have to be obvious, like a haunted house or a dark alley or something (but of course they work too). There are settings like clubs, mansions, and penthouses in my novel, none of which are inherently dark, but when described properly can give off a sense of evil and/or dread. Yet again, usage of "negative" diction can be helpful. If you're describing a wrought-iron fence, say that its posts are "cruelly sharp" or something like that. Again I'm just throwing this stuff out there off the top of my head but still that's the basic concept behind it. Really though it's a hard thing to tell someone how to do, just keep writing and reading other "dark" stories (and good ones at that) and eventually you'll get there. I'm still working on this in my own novel as we speak.
Many stories are shown in all shades of darkness and light, jumping from horribly cynical to happy sunshine days.
I´d suggest turning the views of your main character into negativity. Because it dosen´t matter if the sun is shining over a patch of roses, or the kids are laughing and running on the grass, as long as the character has a negative way of thinking he or she will always see the dark side of things. For example, the sun rays will burn the roses who in return will cut the kids´hands as they deprive the poor things from life by pulling them mercilessly out of the ground.
I write a lot of 'dark' It tends towards violence, death but primarily mental demons. What I find is, while I tend towards that, there is a lot of humour in the story. Perhaps it is gallows humour or it could be keeping the reader immersed in darkness is much more effective if there are flashes of light, otherwise they get desensitized to that dark, foreboding and it doesn't hit them as hard as if they relax for a bit then BAM!