Comments widget input box indistinguishable from rest of comments widget when it has content (microsoft#187819)

Fixes microsoft#187745

Author: alexr00

src/vs/workbench/contrib/comments/browser/media/review.css

@@ -349,6 +349,12 @@
 	outline-width: 1px;
 }
 
+.review-widget .body .comment-form .monaco-editor,
+.review-widget .body .comment-form .monaco-editor .monaco-editor-background,
+.review-widget .body .edit-container .monaco-editor .monaco-editor-background {
+	background-color: var(--vscode-peekViewTitle-background);
+}
+
 .review-widget .body .comment-form .monaco-editor,
 .review-widget .body .edit-container .monaco-editor {
 	width: 100%;