diff --git a/src/display/annotation_layer.js b/src/display/annotation_layer.js
index 0f59633cb..c72625c7c 100644
--- a/src/display/annotation_layer.js
+++ b/src/display/annotation_layer.js
@@ -38,6 +38,7 @@ import {
   warn,
 } from "../shared/util.js";
 import {
+  applyOpacity,
   changeLightness,
   PDFDateString,
   setLayerDimensions,
@@ -232,15 +233,8 @@ class AnnotationElement {
     if (!this.data.color) {
       return null;
     }
-    const [r, g, b] = this.data.color;
-    const opacity = this.data.opacity ?? 1;
-    const oppositeOpacity = 255 * (1 - opacity);
-
-    return changeLightness(
-      Math.min(r + oppositeOpacity, 255),
-      Math.min(g + oppositeOpacity, 255),
-      Math.min(b + oppositeOpacity, 255)
-    );
+    const [r, g, b] = applyOpacity(...this.data.color, this.data.opacity);
+    return changeLightness(r, g, b);
   }
 
   _normalizePoint(point) {
diff --git a/src/display/display_utils.js b/src/display/display_utils.js
index 17ec261da..0cb65303f 100644
--- a/src/display/display_utils.js
+++ b/src/display/display_utils.js
@@ -770,7 +770,24 @@ const SupportedImageMimeTypes = [
   "image/x-icon",
 ];
 
-function changeLightness(r, g, b, lumCallback = l => (1 + Math.sqrt(l)) / 2) {
+class ColorScheme {
+  static get isDarkMode() {
+    return shadow(
+      this,
+      "isDarkMode",
+      !!window?.matchMedia?.("(prefers-color-scheme: dark)").matches
+    );
+  }
+}
+
+function changeLightness(
+  r,
+  g,
+  b,
+  lumCallback = ColorScheme.isDarkMode
+    ? l => (1 - Math.sqrt(1 - l)) / 2
+    : l => (1 + Math.sqrt(l)) / 2
+) {
   r /= 255;
   g /= 255;
   b /= 255;
@@ -803,8 +820,19 @@ function changeLightness(r, g, b, lumCallback = l => (1 + Math.sqrt(l)) / 2) {
   return `hsl(${h}, ${s}%, ${newL}%)`;
 }
 
+function applyOpacity(r, g, b, opacity) {
+  opacity = Math.min(Math.max(opacity ?? 1, 0), 1);
+  const white = 255 * (1 - opacity);
+  r = Math.round(r * opacity + white);
+  g = Math.round(g * opacity + white);
+  b = Math.round(b * opacity + white);
+  return [r, g, b];
+}
+
 export {
+  applyOpacity,
   changeLightness,
+  ColorScheme,
   deprecated,
   fetchData,
   getColorValues,
diff --git a/src/display/editor/comment.js b/src/display/editor/comment.js
index 37ed503f2..f71892321 100644
--- a/src/display/editor/comment.js
+++ b/src/display/editor/comment.js
@@ -58,6 +58,10 @@ class Comment {
           : position[0])
       }% - var(--comment-button-dim))`;
       style.top = `calc(${100 * position[1]}% - var(--comment-button-dim))`;
+      const color = this.#editor.commentButtonColor;
+      if (color) {
+        style.backgroundColor = color;
+      }
     }
 
     return this.#render(button);
diff --git a/src/display/editor/editor.js b/src/display/editor/editor.js
index ee895a905..19d34cf97 100644
--- a/src/display/editor/editor.js
+++ b/src/display/editor/editor.js
@@ -22,13 +22,18 @@ import {
   ColorManager,
   KeyboardManager,
 } from "./tools.js";
+import {
+  applyOpacity,
+  changeLightness,
+  noContextMenu,
+  stopEvent,
+} from "../display_utils.js";
 import {
   FeatureTest,
   MathClamp,
   shadow,
   unreachable,
 } from "../../shared/util.js";
-import { noContextMenu, stopEvent } from "../display_utils.js";
 import { AltText } from "./alt_text.js";
 import { Comment } from "./comment.js";
 import { EditorToolbar } from "./toolbar.js";
@@ -1857,6 +1862,17 @@ class AnnotationEditor {
     return this._uiManager.direction === "ltr" ? [1, 0] : [0, 0];
   }
 
+  get commentButtonColor() {
+    if (!this.color) {
+      return null;
+    }
+    let [r, g, b] = AnnotationEditor._colorManager.convert(
+      this._uiManager.getNonHCMColor(this.color)
+    );
+    [r, g, b] = applyOpacity(r, g, b, this.opacity);
+    return changeLightness(r, g, b);
+  }
+
   /**
    * onkeydown callback.
    * @param {KeyboardEvent} event
diff --git a/src/display/editor/freetext.js b/src/display/editor/freetext.js
index 18b49d3e8..bc47d21c2 100644
--- a/src/display/editor/freetext.js
+++ b/src/display/editor/freetext.js
@@ -35,8 +35,6 @@ const EOL_PATTERN = /\r\n?|\n/g;
  * Basic text editor in order to create a FreeTex annotation.
  */
 class FreeTextEditor extends AnnotationEditor {
-  #color;
-
   #content = "";
 
   #editorDivId = `${this.id}-editor`;
@@ -129,7 +127,7 @@ class FreeTextEditor extends AnnotationEditor {
 
   constructor(params) {
     super({ ...params, name: "freeTextEditor" });
-    this.#color =
+    this.color =
       params.color ||
       FreeTextEditor._defaultColor ||
       AnnotationEditor._defaultLineColor;
@@ -201,7 +199,7 @@ class FreeTextEditor extends AnnotationEditor {
   get propertiesToUpdate() {
     return [
       [AnnotationEditorParamsType.FREETEXT_SIZE, this.#fontSize],
-      [AnnotationEditorParamsType.FREETEXT_COLOR, this.#color],
+      [AnnotationEditorParamsType.FREETEXT_COLOR, this.color],
     ];
   }
 
@@ -215,10 +213,6 @@ class FreeTextEditor extends AnnotationEditor {
     return AnnotationEditorParamsType.FREETEXT_COLOR;
   }
 
-  get colorValue() {
-    return this.#color;
-  }
-
   /**
    * Update the font size and make this action as undoable.
    * @param {number} fontSize
@@ -248,10 +242,10 @@ class FreeTextEditor extends AnnotationEditor {
    */
   #updateColor(color) {
     const setColor = col => {
-      this.#color = this.editorDiv.style.color = col;
+      this.color = this.editorDiv.style.color = col;
       this._colorPicker?.update(col);
     };
-    const savedColor = this.#color;
+    const savedColor = this.color;
     this.addCommands({
       cmd: setColor.bind(this, color),
       undo: setColor.bind(this, savedColor),
@@ -581,7 +575,7 @@ class FreeTextEditor extends AnnotationEditor {
 
     const { style } = this.editorDiv;
     style.fontSize = `calc(${this.#fontSize}px * var(--total-scale-factor))`;
-    style.color = this.#color;
+    style.color = this.color;
 
     this.div.append(this.editorDiv);
 
@@ -819,7 +813,7 @@ class FreeTextEditor extends AnnotationEditor {
     }
     const editor = await super.deserialize(data, parent, uiManager);
     editor.#fontSize = data.fontSize;
-    editor.#color = Util.makeHexColor(...data.color);
+    editor.color = Util.makeHexColor(...data.color);
     editor.#content = FreeTextEditor.#deserializeContent(data.value);
     editor._initialData = initialData;
     if (data.comment) {
@@ -841,9 +835,7 @@ class FreeTextEditor extends AnnotationEditor {
 
     const rect = this.getPDFRect();
     const color = AnnotationEditor._colorManager.convert(
-      this.isAttachedToDOM
-        ? getComputedStyle(this.editorDiv).color
-        : this.#color
+      this.isAttachedToDOM ? getComputedStyle(this.editorDiv).color : this.color
     );
 
     const serialized = {
@@ -895,7 +887,7 @@ class FreeTextEditor extends AnnotationEditor {
     }
     const { style } = content;
     style.fontSize = `calc(${this.#fontSize}px * var(--total-scale-factor))`;
-    style.color = this.#color;
+    style.color = this.color;
 
     content.replaceChildren();
     for (const line of this.#content.split("\n")) {
diff --git a/src/display/editor/highlight.js b/src/display/editor/highlight.js
index 090edf5aa..53f43c8c0 100644
--- a/src/display/editor/highlight.js
+++ b/src/display/editor/highlight.js
@@ -64,8 +64,6 @@ class HighlightEditor extends AnnotationEditor {
 
   #lastPoint = null;
 
-  #opacity;
-
   #outlineId = null;
 
   #text = "";
@@ -108,7 +106,7 @@ class HighlightEditor extends AnnotationEditor {
     super({ ...params, name: "highlightEditor" });
     this.color = params.color || HighlightEditor._defaultColor;
     this.#thickness = params.thickness || HighlightEditor._defaultThickness;
-    this.#opacity = params.opacity || HighlightEditor._defaultOpacity;
+    this.opacity = params.opacity || HighlightEditor._defaultOpacity;
     this.#boxes = params.boxes || null;
     this.#methodOfCreation = params.methodOfCreation || "";
     this.#text = params.text || "";
@@ -361,7 +359,7 @@ class HighlightEditor extends AnnotationEditor {
   #updateColor(color) {
     const setColorAndOpacity = (col, opa) => {
       this.color = col;
-      this.#opacity = opa;
+      this.opacity = opa;
       this.parent?.drawLayer.updateProperties(this.#id, {
         root: {
           fill: col,
@@ -371,7 +369,7 @@ class HighlightEditor extends AnnotationEditor {
       this.#colorPicker?.updateColor(col);
     };
     const savedColor = this.color;
-    const savedOpacity = this.#opacity;
+    const savedOpacity = this.opacity;
     this.addCommands({
       cmd: setColorAndOpacity.bind(
         this,
@@ -549,7 +547,7 @@ class HighlightEditor extends AnnotationEditor {
         root: {
           viewBox: "0 0 1 1",
           fill: this.color,
-          "fill-opacity": this.#opacity,
+          "fill-opacity": this.opacity,
         },
         rootClass: {
           highlight: true,
@@ -951,7 +949,7 @@ class HighlightEditor extends AnnotationEditor {
     const editor = await super.deserialize(data, parent, uiManager);
 
     editor.color = Util.makeHexColor(...color);
-    editor.#opacity = opacity || 1;
+    editor.opacity = opacity || 1;
     if (inkLists) {
       editor.#thickness = data.thickness;
     }
@@ -1046,7 +1044,7 @@ class HighlightEditor extends AnnotationEditor {
     const serialized = {
       annotationType: AnnotationEditorType.HIGHLIGHT,
       color,
-      opacity: this.#opacity,
+      opacity: this.opacity,
       thickness: this.#thickness,
       quadPoints: this.#serializeBoxes(),
       outlines: this.#serializeOutlines(rect),
diff --git a/src/display/editor/ink.js b/src/display/editor/ink.js
index 58afba998..83823f179 100644
--- a/src/display/editor/ink.js
+++ b/src/display/editor/ink.js
@@ -193,10 +193,14 @@ class InkEditor extends DrawingEditor {
     return AnnotationEditorParamsType.INK_COLOR;
   }
 
-  get colorValue() {
+  get color() {
     return this._drawingOptions.stroke;
   }
 
+  get opacity() {
+    return this._drawingOptions["stroke-opacity"];
+  }
+
   /** @inheritdoc */
   onScaleChanging() {
     if (!this.parent) {
diff --git a/src/display/editor/stamp.js b/src/display/editor/stamp.js
index cf5f50d73..a8a615a4a 100644
--- a/src/display/editor/stamp.js
+++ b/src/display/editor/stamp.js
@@ -15,6 +15,7 @@
 
 import { AnnotationEditorType, AnnotationPrefix } from "../../shared/util.js";
 import {
+  ColorScheme,
   OutputScale,
   PixelsPerInch,
   SupportedImageMimeTypes,
@@ -535,7 +536,7 @@ class StampEditor extends AnnotationEditor {
         black = "#cfcfd8";
       if (this._uiManager.hcmFilter !== "none") {
         black = "black";
-      } else if (window.matchMedia?.("(prefers-color-scheme: dark)").matches) {
+      } else if (ColorScheme.isDarkMode) {
         white = "#8f8f9d";
         black = "#42414d";
       }
diff --git a/src/pdf.js b/src/pdf.js
index 7b6954eb6..54bf98079 100644
--- a/src/pdf.js
+++ b/src/pdf.js
@@ -45,13 +45,7 @@ import {
   VerbosityLevel,
 } from "./shared/util.js";
 import {
-  build,
-  getDocument,
-  PDFDataRangeTransport,
-  PDFWorker,
-  version,
-} from "./display/api.js";
-import {
+  applyOpacity,
   changeLightness,
   fetchData,
   getFilenameFromUrl,
@@ -69,6 +63,13 @@ import {
   stopEvent,
   SupportedImageMimeTypes,
 } from "./display/display_utils.js";
+import {
+  build,
+  getDocument,
+  PDFDataRangeTransport,
+  PDFWorker,
+  version,
+} from "./display/api.js";
 import { AnnotationEditorLayer } from "./display/editor/annotation_editor_layer.js";
 import { AnnotationEditorUIManager } from "./display/editor/tools.js";
 import { AnnotationLayer } from "./display/annotation_layer.js";
@@ -98,6 +99,7 @@ globalThis.pdfjsLib = {
   AnnotationLayer,
   AnnotationMode,
   AnnotationType,
+  applyOpacity,
   build,
   changeLightness,
   ColorPicker,
@@ -154,6 +156,7 @@ export {
   AnnotationLayer,
   AnnotationMode,
   AnnotationType,
+  applyOpacity,
   build,
   changeLightness,
   ColorPicker,
diff --git a/test/unit/display_utils_spec.js b/test/unit/display_utils_spec.js
index 34975e554..cb26189d0 100644
--- a/test/unit/display_utils_spec.js
+++ b/test/unit/display_utils_spec.js
@@ -14,6 +14,7 @@
  */
 
 import {
+  applyOpacity,
   changeLightness,
   getFilenameFromUrl,
   getPdfFilenameFromUrl,
@@ -324,4 +325,21 @@ describe("display_utils", function () {
       );
     });
   });
+
+  describe("applyOpacity", function () {
+    it("Check that the opacity is applied correctly", function () {
+      if (isNodeJS) {
+        pending("OffscreenCanvas is not supported in Node.js.");
+      }
+      const canvas = new OffscreenCanvas(1, 1);
+      const ctx = canvas.getContext("2d");
+      ctx.fillStyle = "white";
+      ctx.fillRect(0, 0, 1, 1);
+      ctx.fillStyle = "rgb(123, 45, 67)";
+      ctx.globalAlpha = 0.8;
+      ctx.fillRect(0, 0, 1, 1);
+      const [r, g, b] = ctx.getImageData(0, 0, 1, 1).data;
+      expect(applyOpacity(123, 45, 67, ctx.globalAlpha)).toEqual([r, g, b]);
+    });
+  });
 });
diff --git a/test/unit/pdf_spec.js b/test/unit/pdf_spec.js
index 45ae6a192..8451ec7b3 100644
--- a/test/unit/pdf_spec.js
+++ b/test/unit/pdf_spec.js
@@ -36,13 +36,7 @@ import {
   VerbosityLevel,
 } from "../../src/shared/util.js";
 import {
-  build,
-  getDocument,
-  PDFDataRangeTransport,
-  PDFWorker,
-  version,
-} from "../../src/display/api.js";
-import {
+  applyOpacity,
   changeLightness,
   fetchData,
   getFilenameFromUrl,
@@ -60,6 +54,13 @@ import {
   stopEvent,
   SupportedImageMimeTypes,
 } from "../../src/display/display_utils.js";
+import {
+  build,
+  getDocument,
+  PDFDataRangeTransport,
+  PDFWorker,
+  version,
+} from "../../src/display/api.js";
 import { AnnotationEditorLayer } from "../../src/display/editor/annotation_editor_layer.js";
 import { AnnotationEditorUIManager } from "../../src/display/editor/tools.js";
 import { AnnotationLayer } from "../../src/display/annotation_layer.js";
@@ -82,6 +83,7 @@ const expectedAPI = Object.freeze({
   AnnotationLayer,
   AnnotationMode,
   AnnotationType,
+  applyOpacity,
   build,
   changeLightness,
   ColorPicker,
diff --git a/web/comment_manager.css b/web/comment_manager.css
index 3870819a8..fb19a2b84 100644
--- a/web/comment_manager.css
+++ b/web/comment_manager.css
@@ -257,6 +257,7 @@
 
 :is(.annotationLayer, .annotationEditorLayer) {
   .annotationCommentButton {
+    color-scheme: light dark;
     --comment-button-bg: light-dark(white, #1c1b22);
     --comment-button-fg: light-dark(#5b5b66, #fbfbfe);
     --comment-button-active-bg: light-dark(#0041a4, #a6ecf4);
diff --git a/web/pdfjs.js b/web/pdfjs.js
index 13bf17bb7..c1d0aa59d 100644
--- a/web/pdfjs.js
+++ b/web/pdfjs.js
@@ -22,6 +22,7 @@ const {
   AnnotationLayer,
   AnnotationMode,
   AnnotationType,
+  applyOpacity,
   build,
   changeLightness,
   ColorPicker,
@@ -78,6 +79,7 @@ export {
   AnnotationLayer,
   AnnotationMode,
   AnnotationType,
+  applyOpacity,
   build,
   changeLightness,
   ColorPicker,