hugo-theme-relearn/static/css/theme-green.css

:root {
    --MAIN-TEXT-color:#323232; /* Color of text by default */
    --MAIN-TITLES-TEXT-color: #5e5e5e; /* Color of titles h2-h3-h4-h5-h6 */
    --MAIN-LINK-color:#599a3e; /* Color of links */
    --MAIN-LINK-HOVER-color:#3f6d2c; /* Color of hovered links */
    --MAIN-ANCHOR-color: #599a3e; /* color of anchors on titles */

    --MENU-HOME-LINK-color: #323232; /* Color of the home button text */
    --MENU-HOME-LINK-HOVER-color: #5e5e5e; /* Color of the hovered home button text */

    --MENU-HEADER-BG-color:#74b559; /* Background color of menu header */
    --MENU-HEADER-BORDER-color:#9cd484; /*Color of menu header border */

    --MENU-SEARCH-BG-color:#599a3e; /* Search field background color (by default borders + icons) */
    --MENU-SEARCH-BOX-color: #84c767; /* Override search field border color */
    --MENU-SEARCH-BOX-ICONS-color: #c7f7c4; /* Override search field icons color */

    --MENU-SECTIONS-ACTIVE-BG-color:#1b211c; /* Background color of the active section and its children */
    --MENU-SECTIONS-BG-color:#222723; /* Background color of other sections */
    --MENU-SECTIONS-LINK-color: #ccc; /* Color of links in menu */
    --MENU-SECTIONS-LINK-HOVER-color: #e6e6e6;  /* Color of links in menu, when hovered */
    --MENU-SECTION-ACTIVE-CATEGORY-color: #777; /* Color of active category text */
    --MENU-SECTION-ACTIVE-CATEGORY-BG-color: #fff; /* Color of background for the active category (only) */

    --MENU-VISITED-color: #599a3e; /* Color of 'page visited' icons in menu */
    --MENU-SECTION-HR-color: #18211c; /* Color of <hr> separator in menu */
}