I found an awesome LuCI theme over at the OpenWRT forums. Here are some screenshots.
Required packages: wget, curl, ca-certificates
Here’s how you can install it via shh in Linux:
ssh root@192.168.8.1
mkdir tmp
cd tmp
wget https://github.com/LuttyYang/luci-theme-material/releases/download/v0.2.17/luci-theme-material_0.2.17-1_all.ipk
opkg install luci-theme-material_0.2.17-1_all.ipk
You can switch the theme under System > System > Language and Style.
Enjoy!