diff --git a/src/display/annotation_layer.js b/src/display/annotation_layer.js
index 7e023c67d..80b083c61 100644
--- a/src/display/annotation_layer.js
+++ b/src/display/annotation_layer.js
@@ -2199,23 +2199,7 @@ class PopupElement {
       const baseColor = (popup.style.outlineColor = Util.makeHexColor(
         ...this.#color
       ));
-      if (
-        (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) ||
-        CSS.supports("background-color", "color-mix(in srgb, red 30%, white)")
-      ) {
-        popup.style.backgroundColor = `color-mix(in srgb, ${baseColor} 30%, white)`;
-      } else {
-        // color-mix isn't supported in some browsers hence this version.
-        // See https://developer.mozilla.org/en-US/docs/Web/CSS/color_value/color-mix#browser_compatibility
-        // TODO: Use color-mix when it's supported everywhere.
-        // Enlighten the color.
-        const BACKGROUND_ENLIGHT = 0.7;
-        popup.style.backgroundColor = Util.makeHexColor(
-          ...this.#color.map(c =>
-            Math.floor(BACKGROUND_ENLIGHT * (255 - c) + c)
-          )
-        );
-      }
+      popup.style.backgroundColor = `color-mix(in srgb, ${baseColor} 30%, white)`;
     }
 
     const header = document.createElement("span");