diff --git a/static/event-hub.ts b/static/event-hub.ts
index 14afa1191..606aa29e0 100644
--- a/static/event-hub.ts
+++ b/static/event-hub.ts
@@ -89,26 +89,4 @@ export class EventHub {
         }
         this.subscriptions = [];
     }
-
-    public mediateDependentCalls<T1 extends unknown[], T2 extends unknown[] = T1>(
-        dependent: EventHubCallback<any>,
-        dependency: EventHubCallback<any>,
-    ): DependencyProxies<T1, T2> {
-        let hasDependencyExecuted = false;
-        let lastDependentArguments: unknown[] | null = null;
-        const dependencyProxy = function (this: unknown, ...args: unknown[]) {
-            dependency.apply(this, args);
-            hasDependencyExecuted = true;
-            if (lastDependentArguments) {
-                dependent.apply(this, lastDependentArguments);
-            }
-        };
-        const dependentProxy = function (this: unknown, ...args: unknown[]) {
-            if (hasDependencyExecuted) {
-                dependent.apply(this, args);
-            }
-            lastDependentArguments = args;
-        };
-        return {dependencyProxy, dependentProxy};
-    }
 }
diff --git a/static/panes/ast-view.ts b/static/panes/ast-view.ts
index bd5edefd0..ad24cf1c1 100644
--- a/static/panes/ast-view.ts
+++ b/static/panes/ast-view.ts
@@ -56,9 +56,11 @@ type AstCodeEntry = {
 };
 
 export class Ast extends MonacoPane<monaco.editor.IStandaloneCodeEditor, AstState> {
+    // TODO: eliminate deprecated deltaDecorations monaco API
     decorations: DecorationEntry = {linkedCode: []};
     prevDecorations: any[] = [];
-    colours: string[] = [];
+    colourScheme?: string = undefined;
+    srcColours?: Record<number, number> = undefined;
     astCode: AstCodeEntry[] = [];
     linkedFadeTimeoutId?: NodeJS.Timeout = undefined;
 
@@ -91,11 +93,9 @@ export class Ast extends MonacoPane<monaco.editor.IStandaloneCodeEditor, AstStat
 
         this.container.on('destroy', this.close, this);
 
-        const onColoursOnCompile = this.eventHub.mediateDependentCalls(this.onColours, this.onCompileResult);
-
-        this.eventHub.on('compileResult', onColoursOnCompile.dependencyProxy, this);
+        this.eventHub.on('compileResult', this.onCompileResult, this);
         this.eventHub.on('compiler', this.onCompiler, this);
-        this.eventHub.on('colours', onColoursOnCompile.dependentProxy, this);
+        this.eventHub.on('colours', this.onColours, this);
         this.eventHub.on('panesLinkLine', this.onPanesLinkLine, this);
         this.eventHub.on('compilerClose', this.onCompilerClose, this);
         this.eventHub.on('settingsChange', this.onSettingsChange, this);
@@ -183,6 +183,7 @@ export class Ast extends MonacoPane<monaco.editor.IStandaloneCodeEditor, AstStat
 
         if (result.hasAstOutput) {
             this.showAstResults(result.astOutput);
+            this.tryApplyAstColours();
         } else if (compiler.supportsAstView) {
             this.showAstResults([{text: '<No output>'}]);
         }
@@ -230,27 +231,35 @@ export class Ast extends MonacoPane<monaco.editor.IStandaloneCodeEditor, AstStat
         }
     }
 
-    onColours(id: number, colours: Record<number, number>, scheme: string) {
-        if (id === this.compilerInfo.compilerId) {
-            const astColours = {};
-            for (const [index, code] of this.astCode.entries()) {
-                if (
-                    code.source &&
-                    code.source.from?.line &&
-                    code.source.to?.line &&
-                    code.source.from.line <= code.source.to.line &&
-                    code.source.to.line < code.source.from.line + 100
-                ) {
-                    for (let i = code.source.from.line; i <= code.source.to.line; ++i) {
-                        if (i - 1 in colours) {
-                            astColours[index] = colours[i - 1];
-                            break;
-                        }
+    tryApplyAstColours(): void {
+        if (!this.srcColours || !this.colourScheme || this.astCode.length === 0) return;
+        const astColours = {};
+        for (const [index, code] of this.astCode.entries()) {
+            if (
+                code.source &&
+                code.source.from?.line &&
+                code.source.to?.line &&
+                code.source.from.line <= code.source.to.line &&
+                code.source.to.line < code.source.from.line + 100
+            ) {
+                for (let i = code.source.from.line; i <= code.source.to.line; ++i) {
+                    if (i - 1 in this.srcColours) {
+                        astColours[index] = this.srcColours[i - 1];
+                        break;
                     }
                 }
             }
-            colour.applyColours(astColours, scheme, this.editorDecorations);
         }
+        colour.applyColours(astColours, this.colourScheme, this.editorDecorations);
+    }
+
+    onColours(id: number, srcColours: Record<number, number>, colourScheme: string): void {
+        if (id !== this.compilerInfo.compilerId) return;
+
+        this.srcColours = srcColours;
+        this.colourScheme = colourScheme;
+
+        this.tryApplyAstColours();
     }
 
     updateDecorations() {
diff --git a/static/panes/ir-view.ts b/static/panes/ir-view.ts
index fadd1a9fb..b48ffabef 100644
--- a/static/panes/ir-view.ts
+++ b/static/panes/ir-view.ts
@@ -48,9 +48,13 @@ import {CompilerInfo} from '../compiler.interfaces.js';
 export class Ir extends MonacoPane<monaco.editor.IStandaloneCodeEditor, IrState> {
     linkedFadeTimeoutId: NodeJS.Timeout | null = null;
     irCode: any[] = [];
-    colours: any[] = [];
+    srcColours?: Record<number, number | undefined> = undefined;
+    colourScheme?: string = undefined;
+
+    // TODO: eliminate deprecated deltaDecorations monaco API
     decorations: any = {};
     previousDecorations: string[] = [];
+
     options: Toggles;
     filters: Toggles;
     lastOptions: LLVMIrBackendOptions = {
@@ -168,15 +172,11 @@ export class Ir extends MonacoPane<monaco.editor.IStandaloneCodeEditor, IrState>
     override registerCallbacks(): void {
         const onMouseMove = _.throttle(this.onMouseMove.bind(this), 50);
         const onDidChangeCursorSelection = _.throttle(this.onDidChangeCursorSelection.bind(this), 500);
-        const onColoursOnCompile = this.eventHub.mediateDependentCalls(
-            this.onColours.bind(this),
-            this.onCompileResult.bind(this),
-        );
 
         this.paneRenaming.on('renamePane', this.updateState.bind(this));
 
-        this.eventHub.on('compileResult', onColoursOnCompile.dependencyProxy, this);
-        this.eventHub.on('colours', onColoursOnCompile.dependentProxy, this);
+        this.eventHub.on('compileResult', this.onCompileResult.bind(this));
+        this.eventHub.on('colours', this.onColours.bind(this));
         this.eventHub.on('panesLinkLine', this.onPanesLinkLine.bind(this));
 
         this.editor.onMouseMove(event => onMouseMove(event));
@@ -213,6 +213,7 @@ export class Ir extends MonacoPane<monaco.editor.IStandaloneCodeEditor, IrState>
         if (this.compilerInfo.compilerId !== compilerId) return;
         if (result.hasIrOutput) {
             this.showIrResults(unwrap(result.irOutput).asm);
+            this.tryApplyIrColours();
         } else if (compiler.supportsIrView) {
             this.showIrResults([{text: '<No output>'}]);
         }
@@ -248,20 +249,29 @@ export class Ir extends MonacoPane<monaco.editor.IStandaloneCodeEditor, IrState>
         }
     }
 
-    onColours(compilerId: number, colours: any, scheme: any): void {
-        if (compilerId !== this.compilerInfo.compilerId) return;
+    tryApplyIrColours(): void {
+        if (!this.srcColours || !this.colourScheme || this.irCode.length === 0) return;
+
         const irColours: Record<number, number> = {};
         for (const [index, code] of this.irCode.entries()) {
             if (
                 code.source &&
                 code.source.file === null &&
                 code.source.line > 0 &&
-                colours[code.source.line - 1] !== undefined
+                this.srcColours[code.source.line - 1] !== undefined
             ) {
-                irColours[index] = colours[code.source.line - 1];
+                irColours[index] = this.srcColours[code.source.line - 1]!;
             }
         }
-        applyColours(irColours, scheme, this.editorDecorations);
+        applyColours(irColours, this.colourScheme, this.editorDecorations);
+    }
+
+    onColours(compilerId: number, srcColours: Record<number, number>, scheme: string): void {
+        if (compilerId !== this.compilerInfo.compilerId) return;
+        this.colourScheme = scheme;
+        this.srcColours = srcColours;
+
+        this.tryApplyIrColours();
     }
 
     onMouseMove(e: monaco.editor.IEditorMouseEvent): void {