How to apply custom CSS code. Estimated reading: 1 minute 837 views Contributors You can apply your own custom CSS code on Gullu theme. Your custom CSS code will not be lost even if you update the theme. Navigate to Appearance > Customize > Additional CSS Take a look at the screenshots- How to (FAQs) - Previous How to set site’s favicon Next - How to (FAQs) How to change the transition time of Gullu slider.