diff --git a/addons/mail/static/src/components/thread_preview/thread_preview.scss b/addons/mail/static/src/components/thread_preview/thread_preview.scss
deleted file mode 100644
index e2eed94c50a..00000000000
--- a/addons/mail/static/src/components/thread_preview/thread_preview.scss
+++ /dev/null
@@ -1,7 +0,0 @@
-// ------------------------------------------------------------------
-// Style
-// ------------------------------------------------------------------
-
-.o_ThreadPreview_callIndicator.o-isCalling {
-    color: red;
-}
diff --git a/addons/mail/static/src/components/thread_preview/thread_preview.xml b/addons/mail/static/src/components/thread_preview/thread_preview.xml
index f847bfc96f4..802901d74f7 100644
--- a/addons/mail/static/src/components/thread_preview/thread_preview.xml
+++ b/addons/mail/static/src/components/thread_preview/thread_preview.xml
@@ -35,7 +35,7 @@
                             </span>
                         </t>
                         <t t-if="threadPreviewView.thread.rtcSessions.length > 0">
-                            <span class="o_ThreadPreview_callIndicator fa fa-volume-up mx-2" t-att-class="{ 'o-isCalling': threadPreviewView.thread.rtc }"/>
+                            <span class="o_ThreadPreview_callIndicator fa fa-volume-up mx-2" t-att-class="{ 'o-isCalling text-danger': threadPreviewView.thread.rtc }"/>
                         </t>
                         <span class="o-autogrow"/>
                         <t t-if="threadPreviewView.thread.lastMessage and threadPreviewView.thread.lastMessage.date">