When comparing One Dark vs Leuven, the Slant community recommends One Dark for most people. In the question“What are the best color themes for text editors?” One Dark is ranked 6th while Leuven is ranked 22nd. The most important reason people chose One Dark is:
Its wide hue range with good saturation/value use make a good enough contrast to skim the code fastly and not too vibrant to kill your eyes.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Colors are calm and easy to distinguish
Its wide hue range with good saturation/value use make a good enough contrast to skim the code fastly and not too vibrant to kill your eyes.
Pro Available for vim
Pro Available on a wide range of applications
KDE Plasma, VsCode etc...
Pro Available for Intellij IDEA
Pro Available for Atom clones and Sublime
Possibly for others too
This theme is a default one for Atom text editor.
Pro Default theme for Doom Emacs
Pro Calm blue background
If used with flux, it turns into warm gray during night.
Pro Available as a base16 theme
Pro Includes GUI themes
Pro Helpful for people with astigmatism
People with astigmatism prefer the bright white background since the extra light causes your pupils to contract, which makes your focus sharper.
Pro Helpful for people with deuteranomaly
Leuven is a high-contrast theme preferring blue hues to red ones which makes it easier for people with deuteranomaly (most common form of red-green blindness) to distinguish different syntactical elements.
Cons
Con Ports to other applications are not always accurate.
Con Kind of fadey
The colors aren't that bright (which may be good for some people).
Con May cause eye strain
People with blue-light sensitivity may prefer a dark theme.