userContent.css

/* Incognite mode background color and info */

@-moz-document url("about:privatebrowsing") {

    html.private {
        --in-content-page-background: #1c1b22 !important;
        }

        .info {
            background-color: rgb(255 255 255 / 0.1) !important;
            }

}

/* I don't like cyan */

@-moz-document url-prefix("about:") {

    :root,panel,dialog,window {

        --lwt-toolbarbutton-icon-fill-attention: #99c3ff !important;
        --button-primary-bgcolor: #99c3ff !important;
        --button-primary-hover-bgcolor: #9abaee !important;
        --button-primary-active-bgcolor: #a1c3f9 !important;
        --in-content-primary-button-background: #99c3ff !important;
        --in-content-primary-button-background-hover: #9abaee !important;
        --in-content-primary-button-background-active: #a1c3f9 !important;
        --input-border-color: #99c3ff !important;
        --uc-checkbox-checked-bgcolor: #99c3ff !important;
        --checkbox-checked-bgcolor: #99c3ff !important;
        --focus-outline-color: #99c3ff !important;
        --in-content-link-color: #99c3ff !important;
        --color-accent-primary: #99c3ff !important;
        --color-accent-primary-hover: #9abaee !important;
        --color-accent-primary-active: #a1c3f9 !important;

        }

        }

/* "Your Firefox has been updated" (https://www.mozilla.org/zh-CN/firefox/127.0/whatsnew/) */

@-moz-document url-prefix("https://www.mozilla.org/") {
    @media (prefers-color-scheme: dark) {
        .mzp-c-notification-bar.mzp-t-success {
              background-color: #99c3ff!important;
              }

              }

              }