Merge pull request MicrosoftDocs#3279 from dariomws306/Dariomws-Patch1

Update Set-SPOHideDefaultThemes.md

Author: VesaJuvonen

sharepoint/sharepoint-ps/sharepoint-online/Set-SPOHideDefaultThemes.md

@@ -26,7 +26,10 @@ Specify the setting as either `$true` to hide the default themes, or `$false` (t
 > This cmdlet was named **Set-HideDefaultThemes** until the December 2017 release of the SPO Management Shell. We recommend that you use the latest version of the PowerShell cmdlets.
 
 > [!TIP] 
-> Allows you to hide or show **ALL**  default themes, no any particular ones.
+> Allows you to hide or show **ALL** default themes, no any particular ones.
+
+> [!NOTE] 
+> This cmdlet hides the default themes on **Modern Sites**. You cannot hide the default themes on Classic Sites.
 
 ## EXAMPLES