hugo-theme-relearn/css/theme-red.css

:root {
  --MAIN-TEXT-color: rgba(50, 50, 50, 1); /* Color of text by default */
  --MAIN-TITLES-TEXT-color: rgba(94, 94, 94, 1); /* Color of titles h2-h3-h4-h5-h6 */
  --MAIN-TITLES-H1-TEXT-color: rgba(34, 34, 34, 1); /* text color of h1 titles */
  --MAIN-LINK-color: rgba(243, 28, 28, 1); /* Color of links */
  --MAIN-LINK-HOVER-color: rgba(208, 22, 22, 1); /* Color of hovered links */
  --MAIN-BG-color: rgba(255, 255, 255, 1); /* color of text by default */

  --CODE-theme: learn; /* name of the chroma stylesheet file */
  --CODE-BLOCK-color: rgba(226, 228, 229, 1); /* fallback color for code text */
  --CODE-BLOCK-BG-color: rgba(40, 42, 54, 1); /* fallback color for code background */
  --CODE-BLOCK-BORDER-color: rgba(40, 42, 54, 1); /* color of block code border */
  --CODE-INLINE-color: rgba(94, 94, 94, 1); /* color for inline code text */
  --CODE-INLINE-BG-color: rgba(255, 250, 233, 1); /* color for inline code background */
  --CODE-INLINE-BORDER-color: rgba(248, 232, 200, 1); /* color of inline code border */

  --MENU-HOME-LINK-color: rgba(56, 43, 43, 1); /* Color of the home button text */
  --MENU-HOME-LINK-HOVER-color: rgba(0, 0, 0, 1); /* Color of the hovered home button text */

  --MENU-HEADER-BG-color: rgba(220, 16, 16, 1); /* Background color of menu header */
  --MENU-HEADER-BORDER-color: rgba(226, 49, 49, 1); /*Color of menu header border */

  --MENU-SEARCH-color: rgba(255, 255, 255, 1); /* Color of search field text */
  --MENU-SEARCH-BG-color: rgba(185, 0, 0, 1); /* Search field background color (by default borders + icons) */
  --MENU-SEARCH-BORDER-color: rgba(239, 32, 32, 1); /* Override search field border color */

  --MENU-SECTIONS-ACTIVE-BG-color: rgba(43, 32, 32, 1); /* Background color of the active section and its children */
  --MENU-SECTIONS-BG-color: rgba(49, 37, 37, 1); /* Background color of other sections */
  --MENU-SECTIONS-LINK-color: rgba(204, 204, 204, 1); /* Color of links in menu */
  --MENU-SECTIONS-LINK-HOVER-color: rgba(230, 230, 230, 1); /* Color of links in menu, when hovered */
  --MENU-SECTION-ACTIVE-CATEGORY-color: rgba(119, 119, 119, 1); /* Color of active category text */
  --MENU-SECTION-ACTIVE-CATEGORY-BG-color: rgba(255, 255, 255, 1); /* Color of background for the active category (only) */

  --MENU-VISITED-color: rgba(243, 28, 28, 1); /* Color of 'page visited' icons in menu */
  --MENU-SECTION-SEPARATOR-color: rgba(43, 32, 32, 1); /* Color of <hr> separator in menu */

  /* base styling for boxes */
  --BOX-CAPTION-color: rgba(255, 255, 255, 1); /* color of the title text */
  --BOX-BG-color: rgba(255, 255, 255, 0.833); /* color of the content background */
  --BOX-TEXT-color: rgba(16, 16, 16, 1); /* fixed color of the content text */
}