diff --git a/canvas/src/components/Toolbar.tsx b/canvas/src/components/Toolbar.tsx
index 230e5227..a51e9fa0 100644
--- a/canvas/src/components/Toolbar.tsx
+++ b/canvas/src/components/Toolbar.tsx
@@ -154,10 +154,10 @@ export function Toolbar() {
         {counts.failed > 0 && (
           <StatusPill color={statusDotClass("failed")} count={counts.failed} label="failed" />
         )}
-        <span className="text-ink-soft" aria-hidden="true">·</span>
-        <span className="text-[10px] text-ink-soft whitespace-nowrap">
+        <span className="text-ink-mid" aria-hidden="true">·</span>
+        <span className="text-[10px] text-ink-mid whitespace-nowrap">
           {counts.roots} workspace{counts.roots !== 1 ? "s" : ""}
-          {counts.children > 0 && <span className="text-ink-soft"> + {counts.children} sub</span>}
+          {counts.children > 0 && <span className="text-ink-mid"> + {counts.children} sub</span>}
         </span>
       </div>
 
@@ -172,7 +172,7 @@ export function Toolbar() {
           type="button"
           onClick={stopAll}
           disabled={stopping}
-          className="flex items-center gap-1.5 px-2.5 py-1 bg-red-950/50 hover:bg-red-900/60 border border-red-800/40 rounded-lg transition-colors disabled:opacity-50"
+          className="flex items-center gap-1.5 px-2.5 py-1 bg-bad/10 hover:bg-bad/20 border border-bad/40 rounded-lg transition-colors disabled:opacity-50 focus:outline-none focus-visible:ring-2 focus-visible:ring-bad/40"
           title={`Stop all running tasks (${counts.activeTasks} active)`}
           aria-label={stopping ? "Stopping all running tasks" : `Stop all running tasks (${counts.activeTasks} active)`}
         >
@@ -191,7 +191,7 @@ export function Toolbar() {
           type="button"
           onClick={() => setRestartConfirmOpen(true)}
           disabled={restartingAll}
-          className="flex items-center gap-1.5 px-2.5 py-1 bg-amber-950/40 hover:bg-amber-900/50 border border-amber-800/40 rounded-lg transition-colors disabled:opacity-50"
+          className="flex items-center gap-1.5 px-2.5 py-1 bg-warm/10 hover:bg-warm/20 border border-warm/40 rounded-lg transition-colors disabled:opacity-50 focus:outline-none focus-visible:ring-2 focus-visible:ring-warm/40"
           title={`Restart ${needsRestartNodes.length} workspace${needsRestartNodes.length === 1 ? "" : "s"} that need to pick up config or secret changes`}
           aria-label={restartingAll ? "Restarting workspaces" : `Restart ${needsRestartNodes.length} workspace${needsRestartNodes.length === 1 ? "" : "s"} pending config or secret changes`}
         >
@@ -216,10 +216,10 @@ export function Toolbar() {
         aria-pressed={showA2AEdges}
         aria-label={showA2AEdges ? "Hide A2A edges" : "Show A2A edges"}
         title={showA2AEdges ? "Hide A2A delegation edges" : "Show A2A delegation edges (last 60 min)"}
-        className={`flex items-center justify-center w-7 h-7 border rounded-lg transition-colors ${
+        className={`flex items-center justify-center w-7 h-7 border rounded-lg transition-colors focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40 ${
           showA2AEdges
-            ? "bg-blue-950/50 hover:bg-blue-900/50 border-blue-800/40 text-accent"
-            : "bg-surface-card/50 hover:bg-surface-card/50 border-line/40 text-ink-soft hover:text-ink-mid"
+            ? "bg-accent/15 hover:bg-accent/25 border-accent/50 text-accent"
+            : "bg-surface-card hover:bg-surface-card/70 border-line text-ink-mid hover:text-ink"
         }`}
       >
         {/* Mesh / network icon */}
@@ -255,7 +255,7 @@ export function Toolbar() {
         }}
         aria-label="Open audit trail for selected workspace"
         title="Audit — view ledger for the selected workspace"
-        className="flex items-center justify-center w-7 h-7 bg-surface-card/50 hover:bg-surface-card/50 border border-line/40 rounded-lg transition-colors text-ink-soft hover:text-ink-mid"
+        className="flex items-center justify-center w-7 h-7 bg-surface-card hover:bg-surface-card/70 border border-line rounded-lg transition-colors text-ink-mid hover:text-ink focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40"
       >
         {/* Scroll / ledger icon */}
         <svg
@@ -277,7 +277,7 @@ export function Toolbar() {
         onClick={() => useCanvasStore.getState().setSearchOpen(true)}
         aria-label="Search workspaces"
         title="Search (⌘K)"
-        className="flex items-center justify-center w-7 h-7 bg-surface-card/50 hover:bg-surface-card/50 border border-line/40 rounded-lg transition-colors text-ink-soft hover:text-ink-mid"
+        className="flex items-center justify-center w-7 h-7 bg-surface-card hover:bg-surface-card/70 border border-line rounded-lg transition-colors text-ink-mid hover:text-ink focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40"
       >
         <svg width="14" height="14" viewBox="0 0 16 16" fill="none" aria-hidden="true">
           <circle cx="7" cy="7" r="5" stroke="currentColor" strokeWidth="1.5" />
@@ -290,7 +290,7 @@ export function Toolbar() {
         <button
           type="button"
           onClick={() => setHelpOpen((open) => !open)}
-          className="flex items-center justify-center w-7 h-7 bg-surface-card/50 hover:bg-surface-card/50 border border-line/40 rounded-lg transition-colors text-ink-soft hover:text-ink-mid"
+          className="flex items-center justify-center w-7 h-7 bg-surface-card hover:bg-surface-card/70 border border-line rounded-lg transition-colors text-ink-mid hover:text-ink focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40"
           aria-expanded={helpOpen}
           aria-label="Open quick help"
           title="Help — shortcuts & quick start"
@@ -308,7 +308,7 @@ export function Toolbar() {
               <button
                 type="button"
                 onClick={() => setHelpOpen(false)}
-                className="text-[10px] text-ink-soft hover:text-ink-mid transition-colors"
+                className="text-[10px] text-ink-mid hover:text-ink transition-colors focus:outline-none focus-visible:underline"
               >
                 Close
               </button>
@@ -358,7 +358,7 @@ function WsStatusPill({ status }: { status: "connected" | "connecting" | "discon
     return (
       <div className="flex items-center gap-1.5" title="Real-time updates: connected" aria-label="Real-time updates: connected">
         <div className={`w-1.5 h-1.5 rounded-full ${statusDotClass("online")}`} aria-hidden="true" />
-        <span className="text-[10px] text-ink-soft" aria-hidden="true">Live</span>
+        <span className="text-[10px] text-ink-mid" aria-hidden="true">Live</span>
       </div>
     );
   }
@@ -366,14 +366,14 @@ function WsStatusPill({ status }: { status: "connected" | "connecting" | "discon
     return (
       <div className="flex items-center gap-1.5" title="Real-time updates: reconnecting…" aria-label="Real-time updates: reconnecting">
         <div className="w-1.5 h-1.5 rounded-full bg-amber-400 motion-safe:animate-pulse" aria-hidden="true" />
-        <span className="text-[10px] text-ink-soft" aria-hidden="true">Reconnecting</span>
+        <span className="text-[10px] text-warm" aria-hidden="true">Reconnecting</span>
       </div>
     );
   }
   return (
     <div className="flex items-center gap-1.5" title="Real-time updates: disconnected" aria-label="Real-time updates: disconnected">
       <div className={`w-1.5 h-1.5 rounded-full ${statusDotClass("failed")}`} aria-hidden="true" />
-      <span className="text-[10px] text-ink-soft" aria-hidden="true">Offline</span>
+      <span className="text-[10px] text-bad" aria-hidden="true">Offline</span>
     </div>
   );
 }
@@ -384,7 +384,7 @@ function HelpRow({ shortcut, text }: { shortcut: string; text: string }) {
       <span className="shrink-0 rounded-md border border-line/60 bg-surface/70 px-2 py-0.5 text-[9px] font-medium uppercase tracking-[0.18em] text-ink-mid">
         {shortcut}
       </span>
-      <p className="text-[11px] leading-relaxed text-ink-soft">{text}</p>
+      <p className="text-[11px] leading-relaxed text-ink-mid">{text}</p>
     </div>
   );
 }
diff --git a/workspace-server/migrations/048_activity_logs_peer_indexes.down.sql b/workspace-server/migrations/048_activity_logs_peer_indexes.down.sql
new file mode 100644
index 00000000..f075114e
--- /dev/null
+++ b/workspace-server/migrations/048_activity_logs_peer_indexes.down.sql
@@ -0,0 +1,7 @@
+-- Reverse 048_activity_logs_peer_indexes.up.sql.
+-- Drops the partial peer-conversation indexes added there.
+-- chat_history queries fall back to the existing idx_activity_ws_type_time
+-- + workspace-scoped seq scan / filter on the OR clause.
+
+DROP INDEX IF EXISTS idx_activity_ws_target;
+DROP INDEX IF EXISTS idx_activity_ws_source;
diff --git a/workspace-server/migrations/048_activity_logs_peer_indexes.up.sql b/workspace-server/migrations/048_activity_logs_peer_indexes.up.sql
new file mode 100644
index 00000000..bd4b6888
--- /dev/null
+++ b/workspace-server/migrations/048_activity_logs_peer_indexes.up.sql
@@ -0,0 +1,42 @@
+-- Add per-peer indexes on activity_logs to make chat_history queries
+-- index-driven instead of seq-scan-driven on workspaces with thousands
+-- of accumulated rows. #2478.
+--
+-- chat_history hits:
+--
+--   SELECT ... FROM activity_logs
+--   WHERE workspace_id = $1
+--     AND activity_type = 'a2a_receive'
+--     AND (source_id = $2 OR target_id = $2)
+--   ORDER BY created_at DESC LIMIT 20;
+--
+-- The existing idx_activity_ws_type_time covers workspace_id+type
+-- prefix but the (source_id = $X OR target_id = $X) clause then forces
+-- a workspace-scoped seq-scan-and-filter. Two separate indexes (one per
+-- nullable column) let Postgres BitmapOr them into a workspace-scoped
+-- BitmapAnd against the existing index.
+--
+-- Partial WHERE NOT NULL because most activity rows (heartbeats,
+-- agent_log, memory_write, etc.) have NULL source_id/target_id and
+-- shouldn't bloat the index. Per-row index size drops from ~all rows
+-- to ~A2A-only rows.
+--
+-- Anti-pattern caveat from the issue: a single compound (a, b) index
+-- can't serve `a OR b` — Postgres can only use compound for prefix
+-- match. Two separate indexes + BitmapOr is the right shape.
+--
+-- CONCURRENTLY would be ideal for online deploys, but goose runs
+-- migrations in a single transaction by default which doesn't allow
+-- CONCURRENTLY. The alternative (annotating the migration to skip the
+-- transaction wrapper) is a per-runner concern; leaving as plain
+-- CREATE INDEX so this works under any goose config. activity_logs is
+-- typically <O(100k) rows per workspace × <O(100) workspaces in
+-- production today; the lock is sub-second-scale.
+
+CREATE INDEX IF NOT EXISTS idx_activity_ws_source
+  ON activity_logs(workspace_id, source_id)
+  WHERE source_id IS NOT NULL;
+
+CREATE INDEX IF NOT EXISTS idx_activity_ws_target
+  ON activity_logs(workspace_id, target_id)
+  WHERE target_id IS NOT NULL;