ccc.nvim VS hsluv-lua

A bit niche, but if you regularly work with shell color codes like \033[1;34m, you should also check out ccc.nvim, since it has a setting to provide highlighting for those.

Use use ccc, which is a color highlighter and color picker plugins and makes stuff like this very easy. you configure it to use HSL sliders, but keeping the values in hex, if you want to. https://github.com/uga-rosa/ccc.nvim

If you don't follow new changes, u/uga-rosa added color highlighting functionality (see readme), just like colorizer.lua. So now you plugins serving two functionality: it's a color picker and colorizer.

HSLuv is the colorspace I use, there's a single file Lua lib here. Just put it in your configs so you can require it anywhere

And finally, there are many different ways to define a 'complementary' color. If I take the color you specify, put it into the perceptually uniform HSLuv color space, and then add 180 to the hue (hue starts at 134.6, and the resulting hue is 314.6), I get #4D1947.

It optionally adds colors in between your chosen color stops through a human-friendly color space using HSLuv:

fyi: the Hsluv is coming from https://github.com/hsluv/hsluv-lua