Instagram allows users to personalise their Direct Messages by changing chat colours, backgrounds, and themed designs. Learning How to Change Chat Theme in Instagram is simple. Open Instagram, go to Direct Messages, select a conversation, and tap the person's name at the top. Choose the Theme option, select your preferred design, and apply it. Both participants in the conversation can see the updated theme. Depending on availability, users can also create customised themes with Meta AI. If the Theme option is missing, try updating Instagram, clearing the app cache, logging out and back in, or restarting your device. These simple steps can help make Instagram conversations more personalised and enjoyable.