Org-roam: Graph in dark mode

[Donkeyfish87]

Brief Abstract

Implement a dark mode for the graph.

Long Description

I like consistency between colors. When I have a dark Emacs I'd like to have a dark graph as well.
If it was able to adapt to the current color-scheme that'd be more soothing for my eyes.

This is not particularly critical though, more of a nice touch.

Proposed Implementation (if any)

Seems like there's a chunk of color-codes in the graph.el file, I guess changing them in some way is the proposed solution. Maybe the colors for the chosen color scheme is stored somewhere and is available through some variable, I'm not sure.

[progfolio]

I agree we could definitely do more in terms of customizing the appearance of the graph.
Implementing #494 would be a step in this direction as it would allow us to separate the graphviz backend into its own module which would implement its own graph-building functionality.

I'd have to look into the dot language more, but it would make sense to allow a custom preamble to be inserted similar to Org's #+HTML_HEAD and #+HTML_HEAD_EXTRA.
The remaining ...-extra-config options could be consolidated into a plist or something more coherent as well. A rough sketch:

(setq org-roam-graphviz-options
      '(:edge (:title-length 100
               :dir "back"
               :citation (:title-length 50
                          :dir "back"))
        :config (:rankdir "LR")))

I like the idea of choosing colors based on the current Emacs theme as well.
By addressing this in a generic way, we can allow users to customize the appearance of the graph to their liking.

[zaeph]

I like the idea of choosing colors based on the current Emacs theme as well.
By addressing this in a generic way, we can allow users to customize the appearance of the graph to their liking.

I agree. pdf-view does something similar with its midnight-mode, and it is pretty effective.

[jethrokuan]

This is probably something @goktug97 can consider for org-roam-server?

[goktug97]

This is probably something @goktug97 can consider for org-roam-server?

Awesome idea

https://github.com/org-roam/org-roam-server/commit/591f5d531c4afa163beb974f5398fda83e295666
Dark mode is added

NOTE: I've tried to prevent flickering in dark mode on iframes as best as I can but preview iframes still flicker time to time. Though I think people don't navigate in those frames regularly so it won't be a problem.