ssb: Add a manual theme color picker.

apps/ssb/tf-compose.js

@@ -1,7 +1,7 @@
 import {LitElement, html, unsafeHTML, live} from './lit-all.min.js';
 import * as tfutils from './tf-utils.js';
 import * as tfrpc from '/static/tfrpc.js';
-import {styles} from './tf-styles.js';
+import {styles, generate_theme} from './tf-styles.js';
 import Tribute from './tribute.esm.js';
 
 class TfComposeElement extends LitElement {
@@ -603,6 +603,9 @@ class TfComposeElement extends LitElement {
 						🔐 Encrypt
 					</button>`;
 		let result = html`
+			<style>
+				${generate_theme()}
+			</style>
 			<style>
 				.w3-input:empty::before {
 					content: attr(placeholder);