You can turn off the highlighting of new and recently installed programs in Start menu/Start Screen. There's no direct group policy but you can use a GPP to insert a registry value that does the same thing:

• Location: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
• Name: Start_NotifyNewApps
• Type: DWORD (32-bit)
• Value: set to 0 to turn off highlighting, set to 1 to turn it back on.