Move history diff viewer color style out of CodeMirror theme (#17154)

GitOrigin-RevId: 1fa527542c3b901c731cb79e1a6063e394e4af34

services/web/frontend/js/features/history/extensions/theme.ts

@@ -61,7 +61,6 @@ const baseTheme = EditorView.baseTheme({
     fontSize: 'var(--font-size)',
     fontFamily: 'var(--source-font-family)',
     lineHeight: 'var(--line-height)',
-    color: '#000',
   },
   '.cm-gutters': {
     fontSize: 'var(--font-size)',

services/web/frontend/stylesheets/app/editor/history-react.less

@@ -392,6 +392,7 @@ history-root {
   display: flex;
   flex-direction: column;
   position: relative;
+  color: #000;
 
   .cm-viewer-container,
   .cm-editor {