diff --git a/src/web/public/terminal-ui.js b/src/web/public/terminal-ui.js
index da6a485e..4dc2ef10 100644
--- a/src/web/public/terminal-ui.js
+++ b/src/web/public/terminal-ui.js
@@ -180,13 +180,13 @@
   // global so both terminal-ui.js (main terminal) and panels-ui.js (teammate terminals,
   // a separate IIFE) can read the current skin's palette.
   const CODEMAN_XTERM_THEMES = {
-    og: { background: '#0d0d0d', foreground: '#e0e0e0', cursor: '#e0e0e0', cursorAccent: '#0d0d0d', selection: 'rgba(255,255,255,0.3)', black: '#0d0d0d', red: '#ff6b6b', green: '#51cf66', yellow: '#ffd43b', blue: '#339af0', magenta: '#cc5de8', cyan: '#22b8cf', white: '#e0e0e0', brightBlack: '#495057', brightRed: '#ff8787', brightGreen: '#69db7c', brightYellow: '#ffe066', brightBlue: '#5c7cfa', brightMagenta: '#da77f2', brightCyan: '#66d9e8', brightWhite: '#ffffff' },
-    'daylight-green': { background: '#161b23', foreground: '#dfe6ef', cursor: '#2fd3aa', cursorAccent: '#161b23', selection: 'rgba(47,211,170,0.22)', black: '#161b23', red: '#ff8585', green: '#34d8a0', yellow: '#f0c25a', blue: '#5cc6e8', magenta: '#c79af2', cyan: '#2bcbbb', white: '#dfe6ef', brightBlack: '#5b6675', brightRed: '#ffa0a0', brightGreen: '#5fe6b8', brightYellow: '#ffd884', brightBlue: '#82d4ee', brightMagenta: '#d6b3f7', brightCyan: '#5ee0d4', brightWhite: '#f3f6fa' },
-    'daylight-blue': { background: '#161b23', foreground: '#dfe6ef', cursor: '#38b6f0', cursorAccent: '#161b23', selection: 'rgba(56,182,240,0.22)', black: '#161b23', red: '#ff8585', green: '#34d8a0', yellow: '#f0c25a', blue: '#5cc6e8', magenta: '#c79af2', cyan: '#2bcbbb', white: '#dfe6ef', brightBlack: '#5b6675', brightRed: '#ffa0a0', brightGreen: '#5fe6b8', brightYellow: '#ffd884', brightBlue: '#82d4ee', brightMagenta: '#d6b3f7', brightCyan: '#5ee0d4', brightWhite: '#f3f6fa' },
-    'paper-gray': { background: '#f6f8fa', foreground: '#1f2328', cursor: '#0969da', cursorAccent: '#ffffff', selection: 'rgba(9,105,218,0.2)', black: '#24292f', red: '#cf222e', green: '#1a7f37', yellow: '#9a6700', blue: '#0969da', magenta: '#8250df', cyan: '#1b7c83', white: '#59636e', brightBlack: '#6e7781', brightRed: '#a40e26', brightGreen: '#116329', brightYellow: '#7d4e00', brightBlue: '#0550ae', brightMagenta: '#6639ba', brightCyan: '#116b75', brightWhite: '#1f2328' },
-    'solarized-light': { background: '#fdf6e3', foreground: '#586e75', cursor: '#147ba3', cursorAccent: '#fdf6e3', selection: 'rgba(38,139,210,0.2)', black: '#eee8d5', red: '#dc322f', green: '#758600', yellow: '#9b7800', blue: '#147ba3', magenta: '#d33682', cyan: '#2a9189', white: '#073642', brightBlack: '#93a1a1', brightRed: '#cb4b16', brightGreen: '#657b83', brightYellow: '#586e75', brightBlue: '#268bd2', brightMagenta: '#6c71c4', brightCyan: '#2aa198', brightWhite: '#002b36' },
-    'catppuccin-latte': { background: '#eff1f5', foreground: '#4c4f69', cursor: '#1e66f5', cursorAccent: '#ffffff', selection: 'rgba(30,102,245,0.18)', black: '#5c5f77', red: '#d20f39', green: '#3b8f2b', yellow: '#a86605', blue: '#1e66f5', magenta: '#8839ef', cyan: '#177f86', white: '#6c6f85', brightBlack: '#7c7f93', brightRed: '#b50930', brightGreen: '#2f7622', brightYellow: '#8b5604', brightBlue: '#174fbf', brightMagenta: '#6f2bc5', brightCyan: '#116b71', brightWhite: '#4c4f69' },
-    'rose-pine-dawn': { background: '#faf4ed', foreground: '#575279', cursor: '#286983', cursorAccent: '#fffaf3', selection: 'rgba(40,105,131,0.2)', black: '#575279', red: '#b4637a', green: '#286983', yellow: '#96681f', blue: '#477f91', magenta: '#907aa9', cyan: '#3f7f8b', white: '#6e6a86', brightBlack: '#797593', brightRed: '#984d66', brightGreen: '#1f5266', brightYellow: '#7d5417', brightBlue: '#386b7c', brightMagenta: '#765f90', brightCyan: '#326b76', brightWhite: '#575279' },
+    og: { background: '#0d0d0d', foreground: '#e0e0e0', cursor: '#e0e0e0', cursorAccent: '#0d0d0d', selectionBackground: 'rgba(255,255,255,0.3)', selectionInactiveBackground: 'rgba(255,255,255,0.165)', black: '#0d0d0d', red: '#ff6b6b', green: '#51cf66', yellow: '#ffd43b', blue: '#339af0', magenta: '#cc5de8', cyan: '#22b8cf', white: '#e0e0e0', brightBlack: '#495057', brightRed: '#ff8787', brightGreen: '#69db7c', brightYellow: '#ffe066', brightBlue: '#5c7cfa', brightMagenta: '#da77f2', brightCyan: '#66d9e8', brightWhite: '#ffffff' },
+    'daylight-green': { background: '#161b23', foreground: '#dfe6ef', cursor: '#2fd3aa', cursorAccent: '#161b23', selectionBackground: 'rgba(47,211,170,0.22)', selectionInactiveBackground: 'rgba(47,211,170,0.121)', black: '#161b23', red: '#ff8585', green: '#34d8a0', yellow: '#f0c25a', blue: '#5cc6e8', magenta: '#c79af2', cyan: '#2bcbbb', white: '#dfe6ef', brightBlack: '#5b6675', brightRed: '#ffa0a0', brightGreen: '#5fe6b8', brightYellow: '#ffd884', brightBlue: '#82d4ee', brightMagenta: '#d6b3f7', brightCyan: '#5ee0d4', brightWhite: '#f3f6fa' },
+    'daylight-blue': { background: '#161b23', foreground: '#dfe6ef', cursor: '#38b6f0', cursorAccent: '#161b23', selectionBackground: 'rgba(56,182,240,0.22)', selectionInactiveBackground: 'rgba(56,182,240,0.121)', black: '#161b23', red: '#ff8585', green: '#34d8a0', yellow: '#f0c25a', blue: '#5cc6e8', magenta: '#c79af2', cyan: '#2bcbbb', white: '#dfe6ef', brightBlack: '#5b6675', brightRed: '#ffa0a0', brightGreen: '#5fe6b8', brightYellow: '#ffd884', brightBlue: '#82d4ee', brightMagenta: '#d6b3f7', brightCyan: '#5ee0d4', brightWhite: '#f3f6fa' },
+    'paper-gray': { background: '#f6f8fa', foreground: '#1f2328', cursor: '#0969da', cursorAccent: '#ffffff', selectionBackground: 'rgba(9,105,218,0.2)', selectionInactiveBackground: 'rgba(9,105,218,0.11)', black: '#24292f', red: '#cf222e', green: '#1a7f37', yellow: '#9a6700', blue: '#0969da', magenta: '#8250df', cyan: '#1b7c83', white: '#59636e', brightBlack: '#6e7781', brightRed: '#a40e26', brightGreen: '#116329', brightYellow: '#7d4e00', brightBlue: '#0550ae', brightMagenta: '#6639ba', brightCyan: '#116b75', brightWhite: '#1f2328' },
+    'solarized-light': { background: '#fdf6e3', foreground: '#586e75', cursor: '#147ba3', cursorAccent: '#fdf6e3', selectionBackground: 'rgba(38,139,210,0.2)', selectionInactiveBackground: 'rgba(38,139,210,0.11)', black: '#eee8d5', red: '#dc322f', green: '#758600', yellow: '#9b7800', blue: '#147ba3', magenta: '#d33682', cyan: '#2a9189', white: '#073642', brightBlack: '#93a1a1', brightRed: '#cb4b16', brightGreen: '#657b83', brightYellow: '#586e75', brightBlue: '#268bd2', brightMagenta: '#6c71c4', brightCyan: '#2aa198', brightWhite: '#002b36' },
+    'catppuccin-latte': { background: '#eff1f5', foreground: '#4c4f69', cursor: '#1e66f5', cursorAccent: '#ffffff', selectionBackground: 'rgba(30,102,245,0.18)', selectionInactiveBackground: 'rgba(30,102,245,0.099)', black: '#5c5f77', red: '#d20f39', green: '#3b8f2b', yellow: '#a86605', blue: '#1e66f5', magenta: '#8839ef', cyan: '#177f86', white: '#6c6f85', brightBlack: '#7c7f93', brightRed: '#b50930', brightGreen: '#2f7622', brightYellow: '#8b5604', brightBlue: '#174fbf', brightMagenta: '#6f2bc5', brightCyan: '#116b71', brightWhite: '#4c4f69' },
+    'rose-pine-dawn': { background: '#faf4ed', foreground: '#575279', cursor: '#286983', cursorAccent: '#fffaf3', selectionBackground: 'rgba(40,105,131,0.2)', selectionInactiveBackground: 'rgba(40,105,131,0.11)', black: '#575279', red: '#b4637a', green: '#286983', yellow: '#96681f', blue: '#477f91', magenta: '#907aa9', cyan: '#3f7f8b', white: '#6e6a86', brightBlack: '#797593', brightRed: '#984d66', brightGreen: '#1f5266', brightYellow: '#7d5417', brightBlue: '#386b7c', brightMagenta: '#765f90', brightCyan: '#326b76', brightWhite: '#575279' },
   };
   const CODEMAN_LIGHT_SKINS = new Set(['paper-gray', 'solarized-light', 'catppuccin-latte', 'rose-pine-dawn']);
   function currentSkin() {
diff --git a/test/skin-themes.test.ts b/test/skin-themes.test.ts
index 59e9d28f..f2bd647e 100644
--- a/test/skin-themes.test.ts
+++ b/test/skin-themes.test.ts
@@ -32,6 +32,16 @@ function luminance(hex: string): number {
   return 0.2126 * channels[0] + 0.7152 * channels[1] + 0.0722 * channels[2];
 }
 
+/** Composite an `rgba()` over an opaque `#rrggbb` and return the largest per-channel shift. */
+function channelDelta(background: string, overlay: string): number {
+  const bg = [1, 3, 5].map((i) => parseInt(background.slice(i, i + 2), 16));
+  const m = /rgba\((\d+),\s*(\d+),\s*(\d+),\s*([\d.]+)\)/.exec(overlay);
+  if (!m) throw new Error(`not an rgba() colour: ${overlay}`);
+  const [r, g, b] = [1, 2, 3].map((i) => Number(m[i]));
+  const a = Number(m[4]);
+  return Math.max(...[r, g, b].map((c, i) => Math.abs(Math.round(a * c + (1 - a) * bg[i]) - bg[i])));
+}
+
 function contrastRatio(first: string, second: string): number {
   const [lighter, darker] = [luminance(first), luminance(second)].sort((a, b) => b - a);
   return (lighter + 0.05) / (darker + 0.05);
@@ -64,6 +74,30 @@ describe('Codeman light skins', () => {
     expect(terminal.isLight('daylight-blue')).toBe(false);
   });
 
+  it('paints a selection every skin can actually see', () => {
+    // xterm 6 reads `selectionBackground`; the pre-6 key was `selection`, which it
+    // now IGNORES SILENTLY. Every skin used to carry the old name, so no skin's
+    // tuned selection colour ever applied and xterm fell back to its own default
+    // of white at 30%. On the DARK skins that happens to look right, which is why
+    // it survived — but composited over a light skin's near-white background it
+    // lands ~3/255 away from the background, i.e. dragging highlights nothing and
+    // the terminal reads as "text cannot be selected here".
+    //
+    // Asserting the KEY alone would not have caught it (a badly chosen colour
+    // passes), so this composites the real value over the skin's own background
+    // and demands a visible difference.
+    for (const [skin, theme] of Object.entries(terminal.themes)) {
+      expect(theme.selectionBackground, `${skin} must use xterm 6's selectionBackground`).toBeDefined();
+      expect(theme.selection, `${skin} must not carry the ignored pre-6 'selection' key`).toBeUndefined();
+      expect(theme.selectionInactiveBackground, `${skin} keeps the selection visible unfocused`).toBeDefined();
+      for (const key of ['selectionBackground', 'selectionInactiveBackground'] as const) {
+        expect(channelDelta(theme.background, theme[key]), `${skin}.${key} over its background`).toBeGreaterThanOrEqual(
+          key === 'selectionBackground' ? 12 : 6
+        );
+      }
+    }
+  });
+
   it('provides readable dark-on-light terminal foregrounds', () => {
     for (const skin of LIGHT_SKINS) {
       const theme = terminal.themes[skin];