diff --git a/src/Umbraco.Web.UI.Client/src/core/theme/theme.service.ts b/src/Umbraco.Web.UI.Client/src/core/theme/theme.service.ts
index 34c541aa76..19858b3ede 100644
--- a/src/Umbraco.Web.UI.Client/src/core/theme/theme.service.ts
+++ b/src/Umbraco.Web.UI.Client/src/core/theme/theme.service.ts
@@ -16,13 +16,14 @@ export class UmbThemeService {
 	]);
 	public readonly themes = this.#themes.asObservable();
 
-	#theme = new BehaviorSubject('dark');
+	#theme = new BehaviorSubject('high-contrast');
 	public readonly theme = this.#theme.asObservable();
 
 	#styleElement: HTMLStyleElement;
 
 	constructor() {
 		this.addTheme({ name: 'dark', css: _darkTheme.cssText });
+		this.addTheme({ name: 'high-contrast', css: _hightContrastTheme.cssText });
 		this.#styleElement = document.createElement('style');
 		this.changeTheme(this.#theme.value);
 
@@ -95,3 +96,59 @@ const _darkTheme = css`
 		--uui-color-positive-contrast: #eeeeef;
 	}
 `;
+
+const _hightContrastTheme = css`
+	:root {
+		--uui-color-selected: var(--uui-palette-violet-blue, #3544b1);
+		--uui-color-selected-emphasis: var(--uui-palette-violet-blue-light, rgb(70, 86, 200));
+		--uui-color-selected-standalone: var(--uui-palette-violet-blue-dark, rgb(54, 65, 156));
+		--uui-color-selected-contrast: #fff;
+		--uui-color-current: var(--uui-palette-spanish-pink, #f5c1bc);
+		--uui-color-current-emphasis: var(--uui-palette-spanish-pink-light, rgb(248, 214, 211));
+		--uui-color-current-standalone: var(--uui-palette-spanish-pink-dark, rgb(232, 192, 189));
+		--uui-color-current-contrast: var(--uui-palette-space-cadet, #1b264f);
+		--uui-color-disabled: var(--uui-palette-sand, #f3f3f5);
+		--uui-color-disabled-standalone: var(--uui-palette-sand-dark, rgb(226, 226, 226));
+		--uui-color-disabled-contrast: var(--uui-palette-grey, #c4c4c4);
+		--uui-color-header-surface: var(--uui-palette-space-cadet, #1b264f);
+		--uui-color-header-contrast: #fff;
+		--uui-color-header-contrast-emphasis: #fff;
+		--uui-color-focus: var(--uui-palette-malibu, #3879ff);
+		--uui-color-surface: #fff;
+		--uui-color-surface-alt: #fff;
+		--uui-color-surface-emphasis: #dadada;
+		--uui-color-background: #fff;
+		--uui-color-text: var(--uui-palette-black, #060606);
+		--uui-color-text-alt: var(--uui-palette-dune-black, #2e2b29);
+		--uui-color-interactive: var(--uui-palette-space-cadet, #1b264f);
+		--uui-color-interactive-emphasis: var(--uui-palette-violet-blue, #3544b1);
+		--uui-color-border: #000000;
+		--uui-color-border-standalone: #000000;
+		--uui-color-border-emphasis: #000000;
+		--uui-color-divider: #000000;
+		--uui-color-divider-standalone: #000000;
+		--uui-color-divider-emphasis: #000000;
+		--uui-color-default: var(--uui-palette-space-cadet, #1b264f);
+		--uui-color-default-emphasis: var(--uui-palette-violet-blue, #3544b1);
+		--uui-color-default-standalone: var(--uui-palette-space-cadet-dark, rgb(28, 35, 59));
+		--uui-color-default-contrast: #fff;
+		--uui-color-warning: #ffd621;
+		--uui-color-warning-emphasis: #ffdc41;
+		--uui-color-warning-standalone: #ffdd43;
+		--uui-color-warning-contrast: #000;
+		--uui-color-danger: #c60239;
+		--uui-color-danger-emphasis: #da114a;
+		--uui-color-danger-standalone: #d0003b;
+		--uui-color-danger-contrast: white;
+		--uui-color-positive: #0d8844;
+		--uui-color-positive-emphasis: #159c52;
+		--uui-color-positive-standalone: #1cae5e;
+		--uui-color-positive-contrast: #fff;
+
+		--uui-shadow-depth-1: 0 0 0px 1px black;
+		--uui-shadow-depth-2: 0 0 0px 1px black;
+		--uui-shadow-depth-3: 0 0 0px 1px black;
+		--uui-shadow-depth-4: 0 0 0px 1px black;
+		--uui-shadow-depth-5: 0 0 0px 1px black;
+	}
+`;