Lay the wait palette out instead of picking it

Twenty-three wait categories had colours chosen one at a time, and it
showed. Three failed the 3:1 contrast floor for a graphical object
against the page - Buffer IO sat at 2.00, a blue so dark it was
effectively a hole in the chart. Buffer IO and Parallelism shared an
identical hue. Three oranges sat within 9 degrees of each other, three
pinks within 28, and six near-grey categories were separated by nothing
but lightness, two of them closer than the eye reliably splits.

Now hue carries the family - greens for compute, blues for storage and
network, warm for contention, grey for the buckets that mean "no
information" - and within a family the categories climb a lightness
ladder. That second part is the one that matters for a red-green colour
deficiency, where the hues inside a family collapse and lightness is all
that is left. Every colour clears the contrast floor, nearest neighbours
are 12 apart in CIELAB with normal vision and 6 under simulated
deuteranopia, with no outliers below that. Twenty-three categories
cannot all be distinct by colour alone under that condition, which is
what the legend is for; the ladder keeps neighbours in one chart apart.

The plan viewer had a second, smaller scheme of its own drawn from the
status triad: Lock in the error brush, Network in the success brush, I/O
in the warning brush. That judged - a lock wait is not an error - and it
coupled a wait category to a token meaning something else, so repainting
"error" would have repainted "Lock". It also put red and green on two
categories in a tool for DBAs. Those six now use the identity palette,
which is what that palette asked for: one wait type, one colour,
everywhere.

Verified on screen against SQL2022 as well as by measurement.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017DEJ8FiSKJg44Ew2GG2nQ7

Author: erikdarlingdata

src/PlanViewer.App/Controls/PlanViewerControl.WaitStats.cs

@@ -180,24 +180,30 @@ private static string GetWaitCategory(string waitType)
     }
 
     /// <summary>
-    /// The theme token each wait category is drawn in.
-    ///
-    /// <para>I/O, Lock and Network map onto the semantic tokens that already mean the same thing
-    /// elsewhere (warning, error, ok). CPU takes the Wait Stats panel's own accent. Memory has no
-    /// semantic token of its own, so it borrows the one token left that stays distinct from the
-    /// other five. "Other" is the unclassified bucket and gets the neutral muted foreground, which
-    /// is what it always meant.</para>
+    /// The theme token each wait category is drawn in — the same identity palette the Query Store
+    /// charts use, so a wait type is one colour everywhere in the app.
     /// </summary>
+    /// <remarks>
+    /// <para>These used to be the status triad: Lock drawn in the error brush, Network in the
+    /// success brush, I/O in the warning brush. Two things wrong with that. It judged — a lock wait
+    /// is not an error and a network wait is not a success, and the wait palette's own rule is that
+    /// these classify rather than judge. And it coupled a wait category to a token that means
+    /// something else entirely, so repainting "error" would have quietly repainted "Lock".</para>
+    ///
+    /// <para>It also put red and green on two categories in a tool for DBAs, which is the one pair
+    /// a red-green colour deficiency cannot separate. The identity palette spaces its categories by
+    /// lightness within each hue family for exactly that reason.</para>
+    /// </remarks>
     private static string GetWaitCategoryBrushKey(string category)
     {
         return category switch
         {
-            "CPU" => "InsightWaitsBrush",
-            "I/O" => "WarningBrush",
-            "Lock" => "ErrorBrush",
-            "Memory" => "InsightServerBrush",
-            "Network" => "SuccessBrush",
-            _ => "ForegroundMutedBrush"
+            "CPU" => "WaitCategory.CPU",
+            "I/O" => "WaitCategory.Buffer IO",
+            "Lock" => "WaitCategory.Lock",
+            "Memory" => "WaitCategory.Memory",
+            "Network" => "WaitCategory.Network IO",
+            _ => "WaitCategory.Others"
         };
     }
 }

src/PlanViewer.App/Controls/WaitProfileBarControl.axaml.cs

@@ -132,8 +132,8 @@ private void Redraw()
     private IBrush ResolveBrush(string category, bool isNamed)
     {
         if (!isNamed)
-            return TryFindBrush("WaitCategory.Others", new SolidColorBrush(Color.Parse("#555D66")));
-        return TryFindBrush($"WaitCategory.{category}", new SolidColorBrush(Color.Parse("#555D66")));
+            return TryFindBrush("WaitCategory.Others", new SolidColorBrush(Color.Parse("#676E73")));
+        return TryFindBrush($"WaitCategory.{category}", new SolidColorBrush(Color.Parse("#676E73")));
     }
 
     private IBrush TryFindBrush(string key, IBrush fallback)

src/PlanViewer.App/Controls/WaitStatsProfileControl.axaml.cs

@@ -117,7 +117,7 @@ private void Legend_Click(object? sender, RoutedEventArgs e)
         for (int i = 0; i < AllWaitCategories.Length; i++)
         {
             var cat = AllWaitCategories[i];
-            var brush = TryFindBrush($"WaitCategory.{cat}", new SolidColorBrush(Color.Parse("#555D66")));
+            var brush = TryFindBrush($"WaitCategory.{cat}", new SolidColorBrush(Color.Parse("#676E73")));
 
             var swatch = new Border
             {

src/PlanViewer.App/Controls/WaitStatsRibbonControl.axaml.cs

@@ -293,8 +293,8 @@ private void Redraw()
     private IBrush ResolveBrush(string category, bool isNamed)
     {
         if (!isNamed)
-            return TryFindBrush("WaitCategory.Others", new SolidColorBrush(Color.Parse("#555D66")));
-        return TryFindBrush($"WaitCategory.{category}", new SolidColorBrush(Color.Parse("#555D66")));
+            return TryFindBrush("WaitCategory.Others", new SolidColorBrush(Color.Parse("#676E73")));
+        return TryFindBrush($"WaitCategory.{category}", new SolidColorBrush(Color.Parse("#676E73")));
     }
 
     private IBrush TryFindBrush(string key, IBrush fallback)

src/PlanViewer.App/Themes/DarkTheme.axaml

@@ -229,30 +229,47 @@
     <!-- ===== 7. Wait Stats categories ======================================================== -->
 
     <!-- Fixed per category: the same wait type must keep the same colour across every chart and
-         legend in the app, so these are identity, not palette. Do not reuse them elsewhere. -->
-    <SolidColorBrush x:Key="WaitCategory.Unknown"            Color="#8E8E93"/>
-    <SolidColorBrush x:Key="WaitCategory.CPU"                Color="#00bd23"/>
-    <SolidColorBrush x:Key="WaitCategory.Worker Thread"      Color="#52E3B5"/>
-    <SolidColorBrush x:Key="WaitCategory.Lock"               Color="#EE5A24"/>
-    <SolidColorBrush x:Key="WaitCategory.Latch"              Color="#F368E0"/>
-    <SolidColorBrush x:Key="WaitCategory.Buffer Latch"       Color="#f5069e"/>
-    <SolidColorBrush x:Key="WaitCategory.Buffer IO"          Color="#2d13f2"/>
-    <SolidColorBrush x:Key="WaitCategory.Compilation"        Color="#A29BFE"/>
-    <SolidColorBrush x:Key="WaitCategory.SQL CLR"            Color="#b8dcdc"/>
-    <SolidColorBrush x:Key="WaitCategory.Mirroring"          Color="#54625f"/>
-    <SolidColorBrush x:Key="WaitCategory.Transaction"        Color="#c77416"/>
-    <SolidColorBrush x:Key="WaitCategory.Preemptive"         Color="#FD79A8"/>
-    <SolidColorBrush x:Key="WaitCategory.Service Broker"     Color="#E17055"/>
-    <SolidColorBrush x:Key="WaitCategory.Tran Log IO"        Color="#0984E3"/>
-    <SolidColorBrush x:Key="WaitCategory.Network IO"         Color="#75bbf8"/>
-    <SolidColorBrush x:Key="WaitCategory.Parallelism"        Color="#7B4FFF"/>
-    <SolidColorBrush x:Key="WaitCategory.Memory"             Color="#FDCB6E"/>
-    <SolidColorBrush x:Key="WaitCategory.Tracing"            Color="#B2BEC3"/>
-    <SolidColorBrush x:Key="WaitCategory.Full Text Search"   Color="#DFE6E9"/>
-    <SolidColorBrush x:Key="WaitCategory.Other Disk IO"      Color="#636E72"/>
-    <SolidColorBrush x:Key="WaitCategory.Replication"        Color="#81ECEC"/>
-    <SolidColorBrush x:Key="WaitCategory.Log Rate Governor"  Color="#FAB1A0"/>
-    <SolidColorBrush x:Key="WaitCategory.Others"             Color="#555D66"/>
+         legend in the app, so these are identity, not palette. Do not reuse them elsewhere.
+
+         Laid out rather than picked. Hue carries the family — greens for compute, blues for storage
+         and network, warm for contention, grey for the buckets that mean "no information" — and
+         WITHIN a family the categories are spaced up a lightness ladder. That second part is what
+         makes the chart readable to a red-green colour deficiency, where the hues inside a family
+         collapse together and lightness is all that survives. Twenty-three categories cannot all be
+         told apart by colour alone under that condition; the ladder is what keeps neighbours in the
+         same chart from merging, and the legend is what answers the rest.
+
+         Every colour clears 3:1 against the page background, which is the floor for a graphical
+         object you are expected to read. Three of them used to fail it — Buffer IO sat at 2.00,
+         a saturated blue so dark it was effectively a hole in the chart — and two pairs shared a
+         hue outright. Nearest neighbours are now 12 apart in CIELAB with normal vision and 6 under
+         simulated deuteranopia, with no outliers below that.
+
+         If you repaint one, check it against its family's ladder and re-measure both numbers. -->
+    <!-- Highlight is the selection stroke, not a category: white, and it stays that way. -->
+    <SolidColorBrush x:Key="WaitCategory.Unknown"            Color="#9CA1A5"/>
+    <SolidColorBrush x:Key="WaitCategory.CPU"                Color="#3EBD50"/>
+    <SolidColorBrush x:Key="WaitCategory.Worker Thread"      Color="#72E1A9"/>
+    <SolidColorBrush x:Key="WaitCategory.Lock"               Color="#FB6640"/>
+    <SolidColorBrush x:Key="WaitCategory.Latch"              Color="#FEB5ED"/>
+    <SolidColorBrush x:Key="WaitCategory.Buffer Latch"       Color="#E8469D"/>
+    <SolidColorBrush x:Key="WaitCategory.Buffer IO"          Color="#238CFA"/>
+    <SolidColorBrush x:Key="WaitCategory.Compilation"        Color="#A1A3FB"/>
+    <SolidColorBrush x:Key="WaitCategory.SQL CLR"            Color="#63C5C6"/>
+    <SolidColorBrush x:Key="WaitCategory.Mirroring"          Color="#30907E"/>
+    <SolidColorBrush x:Key="WaitCategory.Transaction"        Color="#DB9027"/>
+    <SolidColorBrush x:Key="WaitCategory.Preemptive"         Color="#FFA8C0"/>
+    <SolidColorBrush x:Key="WaitCategory.Service Broker"     Color="#FF9289"/>
+    <SolidColorBrush x:Key="WaitCategory.Tran Log IO"        Color="#8AC6FF"/>
+    <SolidColorBrush x:Key="WaitCategory.Network IO"         Color="#BBE2FE"/>
+    <SolidColorBrush x:Key="WaitCategory.Parallelism"        Color="#9A84FE"/>
+    <SolidColorBrush x:Key="WaitCategory.Memory"             Color="#FFE6B1"/>
+    <SolidColorBrush x:Key="WaitCategory.Tracing"            Color="#BDC8CE"/>
+    <SolidColorBrush x:Key="WaitCategory.Full Text Search"   Color="#D8F2FC"/>
+    <SolidColorBrush x:Key="WaitCategory.Other Disk IO"      Color="#0FB3E2"/>
+    <SolidColorBrush x:Key="WaitCategory.Replication"        Color="#5DF9ED"/>
+    <SolidColorBrush x:Key="WaitCategory.Log Rate Governor"  Color="#FFCACA"/>
+    <SolidColorBrush x:Key="WaitCategory.Others"             Color="#676E73"/>
     <SolidColorBrush x:Key="WaitCategory.Highlight"          Color="#FFFFFF"/>
 
 </ResourceDictionary>