diff --git a/web/modals/threads/color-selector-button.react.js b/web/modals/threads/color-selector-button.react.js
--- a/web/modals/threads/color-selector-button.react.js
+++ b/web/modals/threads/color-selector-button.react.js
@@ -2,6 +2,7 @@
 
 import classNames from 'classnames';
 import * as React from 'react';
+import tinycolor from 'tinycolor2';
 
 import css from './color-selector-button.css';
 
@@ -13,7 +14,7 @@
 function ColorSelectorButton(props: ColorSelectorButtonProps): React.Node {
   const { color, currentColor, onColorSelection } = props;
 
-  const active = color.toLowerCase() === currentColor.toLowerCase();
+  const active = tinycolor.equals(color, currentColor);
   const containerClassName = classNames(css.container, {
     [css.active]: active,
   });