@RajaputanaN 

check below

Solved: Change work notes color in the Activity formatter ... - ServiceNow Community

Configure journal field tile icons and colors in Configurable Workspace  

💡 If my response helped, please mark it as correct and close the thread 🔒— this helps future readers find the solution faster! 🙏

Regards,
Ankur
Certified Technical Architect  ||  10x ServiceNow MVP  ||  ServiceNow Community Leader