DisableEventIndexDialog: Turn the cancel button red.

res/css/_common.scss

@@ -414,6 +414,11 @@ input[type=text]:focus, input[type=password]:focus, textarea:focus {
     color: $accent-fg-color;
 }
 
+.mx_Dialog button.warning, .mx_Dialog input[type="submit"].warning {
+    border: solid 1px $warning-color;
+    color: $warning-color;
+}
+
 .mx_Dialog button:disabled, .mx_Dialog input[type="submit"]:disabled {
     background-color: $light-fg-color;
     border: solid 1px $light-fg-color;

src/async-components/views/dialogs/eventindex/DisableEventIndexDialog.js

@@ -63,6 +63,7 @@ export default class DisableEventIndexDialog extends React.Component {
                     primaryButton={_t('Disable')}
                     onPrimaryButtonClick={this._onDisable}
                     primaryButtonClass="danger"
+                    cancelButtonClass="warning"
                     onCancel={this.props.onFinished}
                     disabled={this.state.disabling}
                 />