ssb: Add a manual theme color picker.

apps/ssb/tf-tab-news-feed.js

@@ -1,6 +1,6 @@
 import {LitElement, cache, html, unsafeHTML, until} from './lit-all.min.js';
 import * as tfrpc from '/static/tfrpc.js';
-import {styles} from './tf-styles.js';
+import {styles, generate_theme} from './tf-styles.js';
 
 class TfTabNewsFeedElement extends LitElement {
 	static get properties() {
@@ -538,6 +538,9 @@ class TfTabNewsFeedElement extends LitElement {
 			`;
 		}
 		return cache(html`
+			<style>
+				${generate_theme()}
+			</style>
 			${this.unread_allowed()
 				? html`<button
 						class="w3-button w3-theme-d1"