Eldritch is a community-driven dark theme inspired by Lovecraftian horror. With tones from the dark abyss and an emphasis on green and blue, it caters to those who appreciate the darker side of life.

Main Theme repo can be found here

1. Open extension of your choice
2. Add new script
3. Install from URL and paste the following URL:

https://raw.github.com/eldritch-theme/duckduckgo/master/script.js

4. Reload the page

1. Open the developer console (F12)
2. Go to Console tab
3. Paste the following code and press Enter:

var eldritch=["kae"="t","k5"="2","ku"="-1","kk21"="323449","ky"="323449","kkj"="323449","kkx"="04d1f9","kk7"="212337","kk8"="ebfafa","kk9"="37f499","kkaa"="a48cf2","kks"="t","kkw"="s","kkt"="g","kka"="g","kk1"="-1","kkav"="1","kkc"="1","kav"="1","kn"="1","k1"="-1","kak"="-1","kax"="-1","kaq"="-1","kap"="-1","kao"="-1","kau"="-1","ks"="n","kw"="w","ko"="1","ksn"="5","k7"="212337","k8"="ebfafa","k9"="37f499","km"="l","kj"="282a36","kaa"="a48cf2","kx"="04d1f9","kai"="1","kf"="1","k21"="323449","kaf"="b","kac"="1","kt"="e","ka"="e","k18"="1"];for(var i=0;i<eldritch.length;i++)document.cookie=eldritch[i];alert('Appearance settings have successfully been updated!');location.reload();

1. If you prefer not to use cookies, you can use DuckDuckGo's parameters via URL query params: https://duckduckgo.com/?kae=t&k5=2&ku=-1&kk21=323449&ky=323449&kkj=323449&kkx=04d1f9&kk7=212337&kk8=ebfafa&kk9=37f499&kkaa=a48cf2&kks=t&kkw=s&kkt=g&kka=g&kk1=-1&kkav=1&kkc=1&kav=1&kn=1&k1=-1&kak=-1&kax=-1&kaq=-1&kap=-1&kao=-1&kau=-1&ks=n&kw=w&ko=1&ksn=5&k7=212337&k8=ebfafa&k9=37f499&km=l&kj=282a36&kaa=a48cf2&kx=04d1f9&kai=1&kf=1&k21=323449&kaf=b&kac=1&kt=e&ka=e&k18=1 although this will not keep the settings between sessions.