When comparing Zenburn vs Everforest, the Slant community recommends Zenburn for most people. In the question“What are the best VIM color-schemes?” Zenburn is ranked 11th while Everforest is ranked 25th.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Exceptionally easy for your eyes
Pro A battle-tested solution backed by decades of happy use
Pro Low contrast color theme
The low contrast will reduce eyestrain.
Pro Ported to a lot of apps and software
Pro Supports light backgrounds
Includes consistent color palettes for both dark and light modes.
Pro Broad syntax and plugin support
Fine-turned for a wide range of third-party syntaxes and plugins, including Neovim's LSP and Treesitter.
Pro Italics support
If enabled, highlights comments and selected keywords in italics.
Pro Soothing green tones
A calm green-based color scheme which doesn't forget about warm colors.
Cons
Con Quite low in contrast
While the low contrast reduces eye strain, some people may prefer the added legibility of a higher contrast.
Con Colorful
Despite being primarily beige and green toned, the color scheme makes use of warm colors for some syntax highlighting groups, which can outshine the "calm" feeling in certain languages.