Create CSS variables for common noVNC-colors

app/styles/base.css

@@ -53,7 +53,7 @@ html {
 }
 
 .noVNC_disabled {
-    color: rgb(128, 128, 128);
+    color: var(--novnc-grey);
 }
 
 /* ----------------------------------------
@@ -241,7 +241,7 @@ html {
 
     transition: 0.5s ease-in-out;
 
-    background-color: rgb(110, 132, 163);
+    background-color: var(--novnc-blue);
     border-radius: 0 10px 10px 0;
 
     user-select: none;
@@ -286,7 +286,7 @@ html {
     z-index: -1;
     cursor: pointer;
     border-radius: 5px;
-    background-color: rgb(83, 99, 122);
+    background-color: var(--novnc-darkblue);
     background-image: url("../images/handle_bg.svg");
     background-repeat: no-repeat;
     background-position: right;
@@ -371,7 +371,7 @@ html {
     opacity: 0;
     transition: 0.2s ease-in-out;
     background: transparent;
-    box-shadow: 0 0 10px black, inset 0 0 10px 10px rgba(110, 132, 163, 0.8);
+    box-shadow: 0 0 10px black, inset 0 0 10px 10px var(--novnc-darkblue);
     border-radius: 10px;
     transition-delay: 0s;
 }
@@ -478,7 +478,7 @@ html {
 
 .noVNC_panel hr {
     border: none;
-    border-top: 1px solid rgb(192, 192, 192);
+    border-top: 1px solid var(--novnc-lightgrey);
 }
 
 .noVNC_panel label {
@@ -499,7 +499,7 @@ html {
 }
 
 .noVNC_panel .noVNC_heading {
-    background-color: rgb(110, 132, 163);
+    background-color: var(--novnc-blue);
     border-radius: 5px;
     padding: 5px;
     /* Compensate for padding in image */
@@ -577,7 +577,7 @@ html {
 }
 
 #noVNC_modifiers {
-    background-color: rgb(92, 92, 92);
+    background-color: var(--novnc-darkgrey);
     border: none;
     padding: 10px;
 }
@@ -745,7 +745,7 @@ html {
 #noVNC_connect_dlg div {
     padding: 12px;
 
-    background-color: rgb(110, 132, 163);
+    background-color: var(--novnc-blue);
     border-radius: 12px;
     text-align: center;
     font-size: 20px;
@@ -758,17 +758,17 @@ html {
 
     cursor: pointer;
 
-    border-color: rgb(83, 99, 122);
+    border-color: var(--novnc-darkblue);
     border-radius: 5px;
 
-    background: linear-gradient(to top, rgb(110, 132, 163), rgb(99, 119, 147));
+    background: linear-gradient(to top, var(--novnc-blue), rgb(99, 119, 147));
     color: white;
 
     /* This avoids it jumping around when :active */
     vertical-align: middle;
 }
 #noVNC_connect_button:hover {
-    background: linear-gradient(to top, rgb(110, 132, 163), rgb(105, 125, 155));
+    background: linear-gradient(to top, var(--novnc-blue), rgb(105, 125, 155));
 }
 
 #noVNC_connect_button img {
@@ -892,13 +892,13 @@ html {
 }
 
 .noVNC_logo {
-    color:yellow;
+    color: var(--novnc-yellow);
     font-family: 'Orbitron', 'OrbitronTTF', sans-serif;
     line-height: 0.9;
     text-shadow: 0.1em 0.1em 0 black;
 }
 .noVNC_logo span{
-    color:green;
+    color: var(--novnc-green);
 }
 
 #noVNC_bell {

app/styles/constants.css

@@ -0,0 +1,21 @@
+/*
+ * noVNC general CSS constant variables
+ * Copyright (C) 2025 The noVNC authors
+ * noVNC is licensed under the MPL 2.0 (see LICENSE.txt)
+ * This file is licensed under the 2-Clause BSD license (see LICENSE.txt).
+ */
+
+/* ---------- COLORS ----------- */
+
+:root {
+    --novnc-grey: rgb(128, 128, 128);
+    --novnc-lightgrey: rgb(192, 192, 192);
+    --novnc-darkgrey: rgb(92, 92, 92);
+
+    --novnc-blue: rgb(110, 132, 163);
+    --novnc-lightblue: rgb(74, 144, 217);
+    --novnc-darkblue: rgb(83, 99, 122);
+
+    --novnc-green: rgb(0, 128, 0);
+    --novnc-yellow: rgb(255, 255, 0);
+}

app/styles/input.css

@@ -21,7 +21,7 @@ input, input::file-selector-button, button, select, textarea {
     background: none;
 
     padding: 0.5em var(--input-xpadding);
-    border: 1px solid rgb(192, 192, 192);
+    border: 1px solid var(--novnc-lightgrey);
     border-radius: 5px;
     color: black;
     --bg-gradient: linear-gradient(to top, rgb(255, 255, 255) 80%, rgb(240, 240, 240));
@@ -101,8 +101,8 @@ input[type=checkbox] {
     transition: 0.2s background-color linear;
 }
 input[type=checkbox]:checked {
-    background-color: rgb(110, 132, 163);
-    border-color: rgb(110, 132, 163);
+    background-color: var(--novnc-blue);
+    border-color: var(--novnc-blue);
 }
 input[type=checkbox]:checked::after {
     content: "";
@@ -127,7 +127,7 @@ input[type=radio] {
     transition: 0.2s border linear;
 }
 input[type=radio]:checked {
-    border: 6px solid rgb(110, 132, 163);
+    border: 6px solid var(--novnc-blue);
 }
 
 /*
@@ -143,12 +143,12 @@ input[type=range] {
 /* -webkit-slider.. & -moz-range.. cant be in selector lists:
    https://bugs.chromium.org/p/chromium/issues/detail?id=1154623 */
 input[type=range]::-webkit-slider-runnable-track {
-    background-color: rgb(110, 132, 163);
+    background-color: var(--novnc-blue);
     height: 6px;
     border-radius: 3px;
 }
 input[type=range]::-moz-range-track {
-    background-color: rgb(110, 132, 163);
+    background-color: var(--novnc-blue);
     height: 6px;
     border-radius: 3px;
 }
@@ -239,7 +239,7 @@ input:focus-visible::file-selector-button,
 button:focus-visible,
 select:focus-visible,
 textarea:focus-visible {
-    outline: 2px solid rgb(74, 144, 217);
+    outline: 2px solid var(--novnc-lightblue);
     outline-offset: 1px;
 }
 input[type=file]:focus-visible {

vnc.html

@@ -37,6 +37,7 @@
     <link rel="apple-touch-icon" sizes="180x180" type="image/png" href="app/images/icons/novnc-ios-180.png">
 
     <!-- Stylesheets -->
+    <link rel="stylesheet" href="app/styles/constants.css">
     <link rel="stylesheet" href="app/styles/base.css">
     <link rel="stylesheet" href="app/styles/input.css">