Basic.css/css/theme/light-classic.css

:root{
    --c1:#ff8e3c;
    --c2:#fff;
    --c3:#eff0f3;
    --c4:#2a2a2a;
    --c5:#fff;
    }

    blockquote {border-left: 5px solid var(--c1)}
    thead,tfoot {background: var(--c1)}