diff --git a/common/changes/@uifabric/styling/palette-not-optional_2017-06-07-06-56.json b/common/changes/@uifabric/styling/palette-not-optional_2017-06-07-06-56.json
new file mode 100644
index 0000000000000..919622252dcf8
--- /dev/null
+++ b/common/changes/@uifabric/styling/palette-not-optional_2017-06-07-06-56.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@uifabric/styling",
+      "comment": "ITheme: Make palette a required prop",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@uifabric/styling",
+  "email": "chrisgo@microsoft.com"
+}
\ No newline at end of file
diff --git a/common/changes/office-ui-fabric-react/palette-not-optional_2017-06-07-06-56.json b/common/changes/office-ui-fabric-react/palette-not-optional_2017-06-07-06-56.json
new file mode 100644
index 0000000000000..b0fe8eef65633
--- /dev/null
+++ b/common/changes/office-ui-fabric-react/palette-not-optional_2017-06-07-06-56.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "office-ui-fabric-react",
+      "comment": "ITheme: Make palette a required prop",
+      "type": "patch"
+    }
+  ],
+  "packageName": "office-ui-fabric-react",
+  "email": "chrisgo@microsoft.com"
+}
\ No newline at end of file
diff --git a/packages/office-ui-fabric-react/src/components/Theme/ThemePage.tsx b/packages/office-ui-fabric-react/src/components/Theme/ThemePage.tsx
index cd61d36733073..b565083304bd1 100644
--- a/packages/office-ui-fabric-react/src/components/Theme/ThemePage.tsx
+++ b/packages/office-ui-fabric-react/src/components/Theme/ThemePage.tsx
@@ -1,5 +1,5 @@
 import * as React from 'react';
-import { loadTheme, FontClassNames, ITheme } from 'office-ui-fabric-react/lib/Styling';
+import { loadTheme, FontClassNames, ITheme, IPalette } from 'office-ui-fabric-react/lib/Styling';
 import { Highlight } from '@uifabric/example-app-base';
 import { defaultTheme } from './defaultTheme';
 import { Callout } from 'office-ui-fabric-react/lib/Callout';
@@ -115,17 +115,17 @@ export class ThemePage extends React.Component<any, any> {
   private _onColorChanged(index: number, newColor: string) {
     let { colors } = this.state;
     let color = colors[index];
-    let theme: ITheme = {};
+    let palette: Partial<IPalette> = {};
 
     color.value = newColor;
 
     for (let i = 0; i < colors.length; i++) {
       let themeColor = colors[i];
 
-      theme[themeColor.key] = themeColor.value;
+      palette[themeColor.key] = themeColor.value;
     }
 
-    loadTheme({ palette: theme });
+    loadTheme({ palette });
 
     // The theme has changed values, but color state is the same. Force an update on the list.
     this.refs.list.forceUpdate();
diff --git a/packages/styling/src/utilities/theme.ts b/packages/styling/src/utilities/theme.ts
index 680ec7dff0b57..a4d6166a9a829 100644
--- a/packages/styling/src/utilities/theme.ts
+++ b/packages/styling/src/utilities/theme.ts
@@ -9,8 +9,8 @@ import {
 } from '../styles/index';
 import { Customizer } from '@uifabric/utilities/lib/index';
 export interface ITheme {
-  palette?: IPalette;
-  fonts?: IFontStyles;
+  palette: IPalette;
+  fonts: IFontStyles;
   semanticColors?: ISemanticColors;
 }
 import { loadTheme as legacyLoadTheme } from '@microsoft/load-themed-styles';
@@ -33,7 +33,7 @@ export function getTheme(): ITheme {
 /**
  * Loads the default global theme definition.
  */
-export function loadTheme(theme: ITheme): void {
+export function loadTheme(theme: Partial<ITheme>): void {
   _theme = createTheme(theme);
 
   // Load the legacy theme from the palette.
@@ -45,7 +45,7 @@ export function loadTheme(theme: ITheme): void {
 /**
  * Creates a custom theme definition which can be used with the Customizer.
  */
-export function createTheme(theme: ITheme): ITheme {
+export function createTheme(theme: Partial<ITheme>): ITheme {
   let newPalette = {
     ..._theme.palette,
     ...theme.palette