@chandrahasan1 This message appears to the user as a standard response at the condition “Ask user to enter time”. (Natural Language > Default Conversation > Standard Responses)
Could you configure the template as mentioned in the below topic by applying a channel specific override at web/mobile SDK to change the font color?
https://test-discourse.kore.ai/t/how-to-use-a-message-node-to-show-an-error-to-the-end-user/822