uptime-kuma/src/assets/vars.scss

$primary: #5cdd8b;
$danger: #dc3545;
$link-color: #111;
$border-radius: .25rem;

$highlight: #7ce8a4;
$highlight-white: #e7faec;

:root {
    --page-background: #fafafa;
    --background-secondary: #d0d3d5;
    --background-4: #d0d3d5;
    --background-ternary: #d0d3d5;
    --main-font-color: #212529;
}

@media (prefers-color-scheme: dark) {
    :root {
        --page-background: #0a0a0a;
        --background-secondary: #656565;
        --background-4: #313131;
        --background-ternary: #a7a7a7;
        --main-font-color: #e4e4e4;
    }
}