After Spring'18 release the the notification bell color is changed to gray from red and this is causing issue for Sales Reps to notice this. We have Themes and Branding with Spring'18 but could not find if we can change the bell color back to red or any deep color. Tried with Customized theme as well but the theme changes the header and not the bell icon or cody image color. We need to change the bell color. Any quick help will be much appreciated.